how much x-men do you know? do you have a free trial to marvel unlimited?
Grand Design is a 6 issue miniseries that covers a LOT of the x-men history and you'll enjoy that
if you want a lot more to read - i would also read a few bits from other x-teams:
-demon bear saga & zeb wells' new mutants
-generation x 1-11
-peter david's x-factor 1-13
-the further adventures of cyclops & phoenix: the origin of mr sinister