In Italy, our cycling experience is limited to a few trips along the coast from the French border to Savona, one trip from Milano to Lago di Garda, and one Easter holiday in Toscana. The Chianti district in Eastern Toscana is quite hilly (would suit fit cyclists best).
Our general impression from being cycling tourists in Italy is good. Please remember travel insurance, use a helmet, lock your bicycles and keep your luggage safe.
Cycling route suggested:
The route below examplifies how nice bike paths and nice places can be combined into a vacation trip. The route can be modified suiting your own needs and interests; most vacations are improved by longer stays (2-3 days) in some places.
Round trip from Firenze (map link)
Firenze – Panzano in Chianti – Monteriggioni – San Gimignano – San Casciano in Val di Pesa – Firenze