I think I was trying to post to this thread yesterday when the forum 'took a tea break'.
The Lonely Planet guide to Cycling in Italy is worth a look.
It's also worth consulting the
Bicitalia site. It's in Italian (although there may be an English bit) but at the very least there is a network map.
The ciclopista del sole runs from the Dolomites before hitting the coast south of Livorno and then on to Sicily. There is a
website. there is also a guidebook and maps, at least for part of the route, from
ediciclo. Their postage rates are quite pricey, so unless you have a big order it's probably better to buy from a bookshop on the way.
The other route you might want to look at (at least for part of the way) is the Via dei Pellegrini which I think is more commonly known as the Via Francigena aka EuroVelo 6. There was a thread about this on Bikeradar recently with some useful links.
As well as Stanfords, I've always found
www.themapshop.co.uk useful. Both have samples of the maps you can look at. Of course you could also get Garmin's CityNavigator Europe or their (pricey) 1:50k Italy Topo mapping.