Here's an interesting and detailed blog of a ride along the river Loire from its source at Le Mont Gerbier de Jonc to the town of Saumur 1000 km downstream. The author has included lots of pictures and information concerning tourist sites, accommodation and the like. The blog exists at two locations. See:http://gerryotrickcyclist.wordpress.com/http://gerryotrickcyclist.blogspot.com/
The second of these has posts in chronological order.