Planning to see X-Men: First Class on June 3rd? Catch up on some classic graphic novels featuring the X-Men.
Charles Xavier (aka Professor X) and Erik Lensherr (aka Magneto) are two young men discovering their powers. Banding together with fellow mutants to stop a threat to the world, a rift grows between the two forces, leading to the founding of Professor X’s X-MEN and Magneto’s Brotherhood, and the beginning of their eternal war.
Also, try some of the classic animated TV series:
Read up on the long history of the X-Men on the Marvel Wiki.