I thought Venice was an open sewer. Go to Florence instead. Egads, it’s home to the most beautiful women in the world.
I’m always amazed when people say things like this. Venice is easily one of the most astonishing cities in the world and people shouldn’t be diverted simply because the water is a little smelly. Venice is hardly an open sewer. And of course, EVERYONE knows that the most beautiful women in the world are found in the south of Spain. 
Herculaneum is quieter, less tour groups and has arguably more impressive buildings.
We’re planning on two days in Florence in between Rome. Unfortunately we’ll be there around the time of the Palio. Neither one of us has any interest in horse races so we’ll leave the rest of Tuscany for another time.
I may just skip it altogether and see Verona or Bologna for a day or two. After reading up I’m beginning to think Tuscany is worthy of an entire trip in itself.
I beginning that about every single region in Italy. It all looks so delightful.
That advice is now out-of-date. This used to happen when Italy had the Lira, with the exchange rate of over 2,000 to the Pound . Now they use the Euro you won’t find this happening.
If you want to see a complete Roman town I would recommend Ostia Antica. This is the old port of Rome buried under sand and mud rather than volcanic ash. It is only a short train ride from Rome, the ruins are really impressive, and - best of all - it is much much quiter than the better known Pompei and Herculaneum. Just individual tourists rather than massive groups and tour guides.
Otherwise I would echo most of the other posts on Rome but I would say don’t get too paranoid about pick-pockets - just be sensible about what you carry and where you carry it.
You don’t say how long you are staying in each place but if it is more than a three or four days think of renting an apartment. There are hundreds in Rome and at not too unreasonable prices (certainly compared to a decent hotel).
If you want more on any Italian destination try the forums on Trip Advisor - the Rome forum in particular is very active and any detailed query is likely to be answered very quickly.
I didn’t mean they should absolutely skip those things, just that they shouldn’t overlook some of the lesser known things.
I’m jealous too! Some people actually get to live there.
While we, here, live in a land of…suburbs.
I want to go break something.
That’s still rapacious. You honestly think $20 for a day pass is reasonable? really? really really? Isn’t the monthly pass for residents about 40E? And the Lido hotels have gratis watertaxis. They don’t check ID. 
Sorry. I just felt every single thing about Venice was designed to fleece tourists (and I was there at an expenses paid conference thingy, so it has nothing to do with the actual amount of money I spent). Not that its not pretty. Its very pretty. From where I sit you can experience the whole good part of Venice in an afternoon’s walk around town. (actually, I felt like I got it from an hour’s layover on my way to Budapest on a prior trip). Kind of like Pisa. Totally worthwhile day trip. Stay there a week… why?
Venice (IMHO) is the most consistently overrated city in Italy. I’d take Padua over it any day of the week. YMMV.
Florence is amazing. Some day I would like to live there, maybe for a month or so when I hit the lottery. The art! The architecture! The shoes! The pastries! Save some $$ for the open air leather market. I got the most divine fur-lined leather gloves there for about $20. [drools]
Obviously you’ve never been to southern Italy. 
You have found some wonderful advice here, so mine will be on the short side.
Pickpockets, bears repeating. Rome is famous for them.
Hotels in the center of Rome are insanely expensive. You can find bed and breakfasts a few minutes from the center at much lower rates. Some have ensuite bathrooms.
Don’t miss Capri if you are in the neighborhood. It is one of the most beautiful places I’ve ever seen. You MUST be in good shape though. That place is a killer of legs.
Carry your own bottle of water, refill at the hotel. If you are caught (like I was) in the Spanish steps, or other tourist trap, and you really need water you will be paying in excess of US$10.00 for an 8oz bottle. Carry some snacks with you too.
Eat where the locals eat. Chances are nobody speaks English (I speak a bit of Italian), but as long as you understand the menu it’ll be OK.
Portions at European restaurants are much smaller than at most American restaurants. I particularly find American portions to be insanely big.
If you visit the Colosseum, those centurions that offer to pose with your for a picture? Be ready to pay them. It isn’t free.
There are Tourist Bureau people in the train central giving out maps. Take advantage of it.
Visiting the Vatican takes a whole day, at the least. Make sure you don’t separate, you’ll get zero assistance from the guards there. It’s easy to separate when you are walking looking at the ceiling.
As a general rule service is courteous in Italy, but you won’t get the level of service you are used in the state. Restaurants is where you go for good food, not for smiles.
If you take a taxi, make sure it is a real, registered taxi. There are ‘pirate taxis’ in the train stations and other tourist hangouts. A fake taxi driver drove off with 50 euros after he drove us from the train station to the hotel (a 5 minute walk). It was our first day in Italy.
You will walk a lot. Even if you (against our best advice) rent a car. European cities are just not designed for car traffic.
Those people selling Prada and Versace stuff off the sidewalk (mostly African immigrants)? Knockoffs.
BTW, I second Matt’s advice. Italy is disorganized (ironic, since I come from the Dominican Rep. We invented disorganized), and the Italians like it like that thankyouverymuch. Things might not be exactly on time, or where they are supposed to be, etc. We found service a bit lacking, but I am not sure if they are just fed up with tourists, they are rude (not unheard of in other metropolis), or they just dislike everybody. Be patient.
Service in restaurants isn’t as fast as you’re used to here, either. Don’t wait until you’re desperately hungry to find a restaurant to eat at. Oh, and I think they think it’s rude to give someone the check without being asked- it would seem like they’re trying to rush you out of there. Ask the server for “il conto”, and make a motion with your hands like your left hand is a pad of paper and you’re writing on it with your right index finger. That usually got the idea across in most of the restaurants we went to in various European countries.
If you have dietary restrictions or are a picky eater, you might want to get a menu reader. These are pocket-size books with names of various foods and other words that you might expect to encounter in a restaurant translated. A menu reader could tell you how to ask if a dish is vegetarian, for example. Mr Neville and I (we keep kosher, but will eat vegetarian dishes or kosher fish in non-kosher restaurants) had no problem finding dishes that were OK for us at restaurants. We ate a lot of pasta, which was just fine with us.
If you don’t speak enough Italian to order what you want, pointing at it on the menu usually works pretty well.
Some of them don’t allow cars in certain sections of the historic downtowns (ie, the places of most interest to tourists), or charge a congestion fee for bringing a car in, like London does. Certainly in all the European cities I’ve been to, the stuff that we wanted to see as tourists was all in one small area of the downtown, which (if it allowed cars) had narrow, winding streets and very minimal parking. There are certainly no large parking lots near the major tourist attractions like the Colosseum or the Forum in Rome. There are plenty of hotels, including reasonably priced ones, in or within walking distance of the tourist areas. Rome does have a subway, which has a Colosseo stop that’s fairly close to the Colosseum and Forum IIRC.
Europe has much better train service than the US does, and its cities tend to be closer to each other than US cities are. Trains are a good option for travelling between cities.
If you want to see the countryside, and you’re comfortable with driving somewhere where the road signs aren’t in English (I’m not), that’s the only time renting a car might make sense. I have heard that the default for rental cars in Europe is stick shift, not automatic- you’ll have to specifically request an automatic, and you might have to pay extra. That’s just what I’ve heard, though- I’ve never actually rented a car in Europe.
Second that. In spades. I think there’s a European thing about not giving people the feeling they’re supposed to leave. You really do need to roll back any expectations that away will be ‘like home’. Which is, after all, the cool thing about going away.
Whatever else you do, do not complain loudly and publicly when something is different from back home and you prefer the way it is at home. That’s pretty much the defining characteristic of the ugly American.
Me three. At least I have a class this quarter on Rome (as in, the whole city) which heavily employs travel guides. I mix it up with some google earth and it’s all good. OTOH, my class is taught by a guy that lives half the time in Rome, and half in LA. He’s got an apartment on the Janiculum (and one in Westwood, I swear I could die with envy). I want to steal his life, even more so now that I find he spends his time riding around on a Vespa or smoking cigarettes in the underground aqueducts or jogging around the Palatine. Pea green with envy, I tells ya!
More related: I understand that Nero’s Domus Aurea is now re-open after a few years of restoration. Renaissance artists used to hang out there in the undergloom to get inspiration and a few actually carved their names into the walls. I think of everything this is what I would most want to see. But then I’m not the one on vacation, so it’s just a suggestion.
We were in Italy in February. It was a coach tour, so we really didn’t get to spend a ton of time anywhere except Rome, but here are a few impressions anyway:
[ul]
[li]I wasn’t a big fan of Venice, but it is a truly unique place. My biggest problem was simply crowds - I’m not crazy about them, and we were there during Carnivale. As soon as the “scheduled” part of the day was done we got the hell away from San Marco square and wandered the back streets and alley ways. I admit - we had a bellini at Harry’s Bar, but it wasn’t really worth the price.[/li][li]We really liked Sorrento, but I can’t exactly tell you why. It’s a small town, there aren’t any big impressive cathedrals or things of the sort, but it was charming nonetheless. The big “industry” there is inlaid wood. I’m sure we paid too much for a couple of boxes, but we liked them anyway. If you’re somewhat adventurous, there are marked walking trails that pass through Sorrento, and go on inland through the hills. A member of our party spent the day on these trails and warned that they can be very poorly marked, so you may accidentally wind up on someone’s property.[/li][li]I was much more impressed with Pompeii than I expected to be. I had no idea as to the size of the place, and how “complete” a city it really was. I wish we could have spent more time there tha we did.[/li][li]Loved Rome. I will second the warnings about pickpockets, and add one about the gypsies. They will typically be carrying babies, and will beg for money for their children. After a couple of polite, “Nos” on my part, one grabbed my arm. I yelled “No!” (in what my wife calls my Bad Dog voice) and twisted out of her grip. Our tour guide said that is a common tactic - while one occupies your attention the other comes behind and lifts your wallet or passport or whatever. She said sometimes they are not even their children, or children at all. She has seen them actually toss a “child” at a tourist so that they would catch it and occupy their hands. Keep an eye out - they’re usually in groups, and once you see them once you’ll start recognizing them in other places, mostly those frequented by tourists. Once we spotted them, we could usually avoid them. If we couldn’t, we would simply walk with a very confident air, and they left us alone. I think they can smell uncertainty and timidity in people.[/li][li]If you want some guidance, but not something too commercial, there are a few outfits that run English-speaking walking tours. We really enjoyed walking in Rome, and only took a taxi when absolutely necessary. Be aware, you can’t simply flag a taxi. You need to find a taxi stand, or call one from a hotel or restaurant. When the taxi is called, you’ll get a little receipt with the taxi number and time called on it. Be forewarned that the meter starts running when you call the taxi, not when you get in it. Having said that, it never took us more than 10 minutes for our cab to arrive, and the drivers were all pleasant and helpful.[/li][/ul]
Have fun. Definitely get off the main thoroughfares and explore the smaller streets and alleys. Lots of cute little trattorias and cafes with good solid food and inexpensive table wine. On the Amalfi Coast, look for wines called “Lacrime de Christo” (Tears of Christ). It’s the local varietal, and quite tasty.
I don’t remember how I got in, but when I was there in the 1970s I was wandering around the Palatine and somehow got myself into the Cryptoporticus. I think I came out in the Forum somewhere.
Are you a graduate or undergraduate in Classics?
That must have been one cool flanerie you had going on there! I think (I hope I’m right, 'cause I’m going to be tested on this on Monday) that the present entrance to the Domus Aurea is through the remains of the Bath of Trajan.
Undergrad. I don’t have the talent or the stomach for grad work. 
I meant to get to this thread a few days ago…but ya know…life happens.
Anyway lots of good advice here. I was in Italy a few years ago, and yes Nero’s Palace was open for tours. I enjoyed that a lot.
This thread has some good advice, and I linked to some older threads in my post. So you can read a lot of advice about Italy in general, and the “Big Three” cities of Rome, Florence, and Venice.
A word about guidebooks. I suggest personally that you buy/check out from the library every single different kind of book you can find. Not only about the indivdual cities, but about Italy in general. Then sit down and read them all. In my experience, every book will have some of the same general sites listed, but then they’ll each have a different selection of smaller sites to see. So I would read them all and make a list of what I thought looked interesting…then I’d research a bit on the web to see if I could find out more information. How accessible was the site? Did I have to make advanced arrangments to get in? Was it near other locations that I could group together in one day? Stuff like that. On one hand the idea of just winging it and seeing what you can see is tempting…on the other there are so many things to see that you’d hate to find out later that you were right around the corner from something fantastic if you’d only have known.
Good luck and have a good trip!
When I am planning a trip to a city I am unfamiliar with I will buy a map in advance , study it and try and memorise the layout of the city centre . So when I arrive there I will have some idea of where the important points of interest are, and not be wandering around with no idea of which direction I am going or where these sites are located. This is especially important in many European cities, few of which are built on a grid system.