Make sure you get an eurail train pass. After that....see do Rome quickly and get outta there. The best city of them all has to be Florence. Near there the Cinque Terra, it begins with Rio Maggiore. There is a walking path that goes along the water to the next 5 towns, Then you take the train out of there. The Amalfi Coast, from Positano to Salerno Sarrento is spectacular. The island of Capri is worth the ferry ride and a day trip. Northern Italy around Lake Como is breathtaking as well. It's hard to go wrong. I did not care for Rome, but I don't do cities very well...I like beauty and interesting shops without hectic stuff. The entire east coast south of Venice down to Brindisi is kinda flat and boring. Stay to the inland or west side. Although you can take the ferry from Brindisi over to Corfu, Greece and that is worth the trip.
Enjoy.
