Just bringing this back to the top, so you might get some answers. If you 'Google', Cyclotourisme, Bretagne Normandie you will get some French websites, and some of these may have an English version or give you links to specific books.
We did a tour of Brittany about ten years ago - St Malo down to Quiberon and back. Can't remember all campsites we stayed on but stayed at Cite d'Aleth at St Malo (very easy cycle into St Malo itself, brilliant views and an interesting walk round the point - lots of fortifications from WWII), Municipal de l'Hallerais at Dinan (very posh municipal, with a swimming pool and a nice ride into Dinan along the river), Municipal des Gayeulles at Rennes, another municipal at Paimpont (which was just a playing field really, but dead cheap, in the forest and near a nice lake and nearby there's apparently a fairy well that has a reputation as a fountain of youth - didn't try it though), another municipal at Penthievre near Quiberon, which is right on the beach, and a couple of farm sites. Didn't have to book anywhere. There are loads of cycle paths running by the canals - also, we found a cycle festival in Rennes (purely by accident, we just happened to be there on the weekend it was on) and they said that there were plans to open up more canal paths, and they were also talking about turning a disused main road from St Malo to Rennes into a cycle path under the name "Route Bleu" so it might be worth googling it to see if it's finished.
Amazing family weekend with old steam engines, classic car displays, market stalls, and full catering and bar. And camping on site - Save £25 by booking in advance.
Topic: Cycling in Normandy & Brittany
