Need some tips on Italy!

Me and my fiance are trying to plan a vacation for 10 days in Italy this summer (sometime between May-July).

We definitely want to hit up Rome, Florence, and Venice. We don't wanna do one of those tour things, so I was wondering if anyone has been there and could give us tips or point us in the right direction. Anything from hotels to transportation to restaruants would help. Thanks guys!