Do check out Vélo Québec's web page (pointed above by ShootingStar). If by any chance you are interested in a supported tour, DO check out the Grand Tour (on Vélo Québec's web site). It's similar to Cycle Oregon: week long, 75-110 km a day, including shortcuts and detours, they carry your gear, you tent out (there are b&b spots but they must all be taken by now). Around 2,000 cyclists. They cook all your meals including lunch, and the food is fantastic. There is a bistro and you can dance until midnight and get up bright and early to ride the next day. It's an UNBELIEVABLE experience, and this year the itinerary takes you along really interesting routes. Highly, highly recommended. A not very expensive considering all the spectacular amenities. Oh and I didn't tell you about the mechanics. They'll even loan you a bike (or a wheel or whatever) if you have an issue with yours.

A great, no-brainer way to discover the province.