Ken Roberts - - Bicycling

web

Bikely has lots of bike routes for places in France.

maps

the Garmin City Navigator Europe NT digital map for GPS covers the roads of France, but I haven't tried it yet.

paper maps

We found the Michelin 1:200000 maps to be pretty good for road bicycling, even if they don't have all the little one-lane paved roads. 

also the IGN 1:100000 topo maps are useful.

and recently there are IGN regional maps at other scales which can be helpful.

guidebooks

Cycling France, by Sally Dillon and others.  Lonely Planet, 2001. 

I recommend this one highly.  Focus is on multi-day point-to-point tours, but there's lots of helpful and interesting info for other styles of riding.  It does have some single-day loops.