I would either buy or borrow a copy of Rick Steves' Italy and use his recommendations. While I was over there, used primarily his recommendations for food (along with Let's Go!, which for the college student is indespenible for cheap places to sleep) and he never steered me wrong. In Venice, there's a great pizza place that he recommends (can't remember and don't have the book anymore) that serves Neopolitan pizza that is divine (if not on the pricey side) and there's also a small cafe-ish type place that he recommends that was quite good, and cheap to boot. In Venice though, my favorite dining experience was walking around starting around dusk and going from enotecha to enotecha (pub crawl) having a half glass of wine and a panini or some other small tidbit of food at each one. It's a great way to spend an evening, as Venice is by far the most pedestrian friendly city in the world (even if you do get lost frequently, but that's half the fun).

I am definitely a self-declared gourmand so the gastronomic delights of Italy are definitely a big reason for me to go. There's also a pretty good city guide for Rome that you can d/l as a PDF from a hotel/hostel called The Beehive that is quite good (and that I will be staying at in Sept.). Also quite a nice hostel (couldn't tell you about the hotel, but stayed in the hostel about 3 years ago), even if it is near the stazzione. They also have an apartment rental service. The guide can be found at http://www.the-beehive.com/recguide.pdf . Very well written by locals (well, transplanted locals) who really know their stuff.