Hey there, I live in italy at the moment, and i STRONGLY advise NOT to get a car, ive driven here in florence, IT IS SCARY.
I know people have been going on about prices of trains, but that certainly is not the case, if you are willing to take the slow trains, which i find more relaxing, i go from Firenze SMN (florence main train station) to viareggio (local beach) bout 120km away, 2 hours on train for 6.40euro's. Florence to Rome, 25 euros,
When you consider london to scunthorpe cost me 80 pound, trains here are cheap,
Places i would recomend, Milan is nice, but far to touristy, Bologna is a wonderful place, oldest university in europe i belive, some nice places to see (still busy - but very cultural)
Lucca, buietful, if your wanting art gallerys florence,
Watchout for street sellers, dont buy printed paintings or anything - if police catch you you get fined, and it can be anywhere from 400 to 1000 euros.
Bag snatchers - italy has got a bad rep for this, but honistly i dont know where from, just be carful, as anywhere you go and you will be fine.
Also, its now getting quite warm here (27 degrees ish everyday) dont get conned into buying water from the tobbacaria's or coffee shops, your looking at 2.50 for a can of coke and 1.50 for a small bottle of water, you will find a super market within 5 minutes of anywhere, much cheaper,
Hope you have a great holiday, italy is awsome, you will love it.
It really depends where you want to go, Lucca is an extreamly nice place, and not as many tourists,
o almost for got to add this
http://www.trenitalia.com/cms/v/index.jsp?vgnextoid=ad1ce14114bc9110VgnVCM10000080a3e90aRCRD
check different days for each place you want to visit, some days you will find cheaper trains, also if you are based in rome, and want to go up north its not worth it for a day, find a hostel or hotel depending on budget, when i get home i will find the place we stayed in bologna and milan (recomend the bologna hotel (17 euros a night -- was awsome)