Here’s a good link for eats. You can search by price level as well. If you have a bunch of tourists, I’d recommend Gino’s East. What unsuspecting kid doesn’t want several mouthfuls of deep-dish 'za?
Pilsen might be interesting, but I’d recommend the Puerto Rican neighborhood…is it on Augusta? Help, Dopers…it’s the one with the huge metal PR-an flag at the end of the street.
Shedd’s good. Millenium Park’s good in the summer. Bring cameras for intersting “Bean” photos (you’ll know what I mena when you see it). Sears Tower is cool…extra points for seeing the Loop on a business day. Remind them it’s impolite to gawk upwards at the Tower while people are trying to cross Wacker or Adams! 
Might not be a bad idea to take them to see the trading floors in the Mercantile Exchange (free and easy to get to from the Sears Tower). It’s a style of trading that’s going away with the newer electronic markets.
If you’re going on an Architectural Tour…go on the River. The one I like boards on Michigan and Wacker (down on the river level…duh!), and the boats are the Little Lady and some other Lady. Great time. nice restaurant named O’Neills (I think) down on the river, right under the shadown of the new Trump Tower.
Lastly, I heartily recommend the Museum of Science and Industry…but it’s a fair bus ride south.
-Cem
Oh, and Navy Pier…dullsville!