Sorry if this falls under the polls rule, I didn't see anything about book recommendations. I am specifically looking for good material on the Battle of Camaron, but general French Foreign Legion history is of interest to me as well.
Kind of late on this! I was searching for something else and saw this question sitting unanswered! This answer I gave on the Foreign Legion recently might be of interest to you, especially the sources I list at the end. Part of it addressed Camerone specifically. Hope that helps.