For concise background information on French authors, it's hard to beat a series called the Dictionary of Literary Biography. The volumes on French authors are in the Reference Collection on the 2nd floor of Alden Library, mostly in the PQ200 call number range and above. Each entry contains an overview of the author's life and writings, illustrations, and a bibliography which can lead you to more information on the author. Highly recommended!
Here are a few additional sources on literary history: