Of of the strategies I found helpful in finding French resources was to ensure that I usedfrançais as one of my search terms and then combined it with other French language search terms (i.e. livre).  Diigo is the search engine that I normally use when looking for teaching resources that have been bookmarked by other teachers.  Take a look.

 Site NameURL Description
Vikidia French language encyclopedia in the style of Wikipedia.  Aimed at ages 8 - 13.
 Il etait une histoire Online stories and read alouds.
La Zone Jeunesse  Radio-Canada (CBC) Youth Zone.  News, videos, games and more.
Project Gutenberg French language, free ebooks (out of copyright) from Project Gutenberg.
 International Children's Library French language books and stories.
Quia - French Many teacher developed activities in a variety of subject areas, developed in French. 
Du plaisier a lire  Books, games and activities (Canadian)