Opening books in French.
General and middlegame books in French
Endgame books in French.
Books on Grand Masters in French.
Books on tournaments in French.
Miscellaneous chess books in French
The best way to become stronger is to improve your game by avoiding errors. It is much more effective than learning new things and studying openings (please note: that should also be done but has no priority when more elementary skills and knowledge are still insufficient). The recommendation in the manuals is to discuss the games with the pupils. That...