I am looking for ways to improve my mathematical French while learning more material about either finite group theory or geometric group theory. In particular, I would love to find a French equivalent to Rotman's group theory book, if possible. As far as geometric group theory goes, I am open to about anything, but I love Cayley graphs and hyperbolic groups. I apologize if this request is too vague, but do any of you have suggestions for French texts in these areas? In terms of mathematical background, I would consider myself a beginner with a decent foundation in these subjects. Thanks in advance!

5$\begingroup$ Serre's book on representation theory or the one on trees. $\endgroup$ – Felipe Voloch May 16 '12 at 22:46

10$\begingroup$ I'm surprised you haven't come across: ams.org/mathscinetgetitem?mr=1086648 $\endgroup$ – Ian Agol May 16 '12 at 22:51

2$\begingroup$ Also: amazon.com/GeometrietheoriegroupeshyperboliquesMathematics/… $\endgroup$ – Steve D May 17 '12 at 0:01

$\begingroup$ @Agol: Some years ago I had to give a course in French to the local group theorists so that they could read the book by Ghys and de la Harpe. $\endgroup$ – Chandan Singh Dalawat May 17 '12 at 3:36
I suggest the survey articles of Séminaire Bourbaki, such as
Ghys, Étienne Groupes aléatoires (d'après Misha Gromov,…). Astérisque No. 294 (2004), viii, 173–204.
Ghys, Étienne Les groupes hyperboliques. Séminaire Bourbaki, 32 (19891990), Exposé No. 722, 36 p.
Tits, Jacques Groupes à croissance polynomiale. Séminaire Bourbaki, 23 (19801981), Exposé No. 572, 13 p.
At a more elementary level, there are short articles on various topics in the Gazette des Mathématiciens, such as
Topologie, théorie des groupes et problèmes de décision by Pierre de la Harpe in volume 125.
At an even more elementary level, there are many highly readable and visually appealing online articles in the Images des Mathématiques
such as this one:
Un concept mathématique, trois notions : Les groupes au XIXe siècle chez Galois, Cayley, Dedekind, by Caroline Ehrhardt.
Happy reading !