Turtles are cool. I would recommend them as pets, provided that you realize what you are getting yourself into. While it may seem like they are simple to care for, they can get a bit involved. They don’t need too much space, so that is one plus, but they do need a tank at least about 4 feet by 2 - 3 feet.
Lighting is also a must. They will need at least one spotlight (heat), plus a fluorescing bulb that provides UVa and UVb rays. This is very important, because these wavelengths, like in humans, are used to produce vitamin D. You have to be very careful what exactly you get when buying a bulb. I would stick with fluorescent lights, rather than filament lights, as the filament lights don’t provide the full required spectrum (only UVa as petcat said). UVb is vitally important. You can use two separate bulbs for UVa and UVb, but I find it is easier to combine the two into one, and have a separate heat lamp. The floresencent bulbs last for ever, but need to be replaced every six months as their UV production drops off. Also, with the fluorescents, you can by bulbs with different levels of UV production, so you can tailor them to your turtles needs.
Food can also be tricky. A truly balanced diet consists of a protein source, and fresh veggies. When they are younger, they require more protein, and the older they get, the more veggies that they will eat. For protein, I would stick with live crickets, freshly shed mealworms, or feeder fish. All of these should be available at any good local pet store, and for cheap as well. With the insects, make sure to gut load them for 24 hours prior to feeding. This means, essentially lots of fresh food and calcium dust. Calcium dust can also be put on their veggies, and shaken on the outside of the insects prior to feeding. I would avoid canned dog and cat foods, as fresh protein sources are cheap, easily available, and generally healthier. I’m not saying that dog food will dramatically shorten their lives, or impact their health in any detrimentally fashion, but for my lizard, and the turtles that I cared for at the local museum, I prefer foods that are more “natural” as opposed to processed, much as I prefer “natural” foods rather than processed for myself. This point really is a judgment call, and for every six herp owners you talk to, you will get seven different answers.
Hmmm, what else….
First, a caveat. For the record, I am not a vet, but I was in charge of animal care at my local museum for two years, plus I own several reptiles of my own. Also, since our local herp vet left, and has yet to be replaced, I have filled in as an emergency care expert for some local. So, while I feel that I have a pretty decent idea of what I have written about, do take it all with a grain of salt and do some research on your own as well. These links may provide some help with your decision:
http://www.anapsid.org is a superb site. Has information on everything about anything scaly and cold-blooded. Of particular interest to you is the bit on box turtles
For lighting info:
If you do get a turtle, this book is a must have.
Philippe De Vosjoli is the expert when it comes to retiles. His books are very well written, and contain very good information.
And, in closing, if you have any other questions, feel free to e-mail me.