Hi, I'll be going through Italy in a couple of week's.
For many of your questions you can check out>
http://bicycletouring101.com/index.html
As to where to go and what to see check out, (Lonely Planet Italy) good book, many tips with some advice.
I've looked for maps but decided to get them when I reach Italy, so far I only got a map of the Benelux area, when I get to Germany I'll stop at a tourist office and pick out a map then and so on.
http://www.geocities.com/xilios/index.html
Stay on smaller roads if you can and try to avoid large cities when possible.
Try this site for some camping places,
http://www.icaro.it/camping/e
Then put the adress of the camp site on this site to find where it is,
http://www.mappy.com/
You can also save some maps on your e-mail so if you get in trouble just find a PC.
I hope this will help you out.