I live in North Western Italy (town:Novara, usually known as the De Agostini Atlas Books home and for the rice fields all around).
1. The best cycling maps for Italy are provided by Touring Club Italiano. You can easily get them by www.ibs.it, great service and low prices, international shipping is usually provided.
Also the Club Alpino Italiano (Italian Alps Club, www.cai.it) is a very good source especially if you want to go across the central Italy mountains like the Gran Sasso Rock or the Appennini landscapes. I am a proud member of it and I could help you to get the right map from the CAI publications.
The best guide book to Italy should be (in my opinion) the Routard guide. It would allow you to avoid any sort of bad experience as a tourist (a great attention of this guide is focused on the restaurants and the hotels or campings, probably the things you have to be more careful for your wallet in Italy).
2.Avoid landing in Rome. The Fiumicino Airport -Rome is probably the worst road ever. Pay also attention to your bike for city-based thieves.
Many holes on the paved roads. N-e- v- e- r bike at night in Rome, no cycle tracks, poor road lights, bad and angry drivers. Believe me.
3.Camping costs: the price may vary but the average is 15 € per night, tent included.
No optionals like laundry or common kitchen are usually provided.
It is not possible to reserve your place. Just go to the camping gate and ask the guys.
A good camping list is www.campeggi.com.
4.Trains: you can take your bike on the train for € 3,50 per day (it doesn't matter where you go, just add it to the passenger tarifs) but the only trains you can use are the Inter Regional or Regional ones, that usually connect the biggest towns and sometimes also the small villages. You are not allowed to take your bike on High Speed (haha) or Intercity trains. Good idea should be taking the train from Siena to Rome.
Contact me if you need more infos and sorry to everybody for my poor English.
Carlo
(My Dawes Horizon is coming from England!!!!!)