So do you have to do something special to prestige. I have never made it that far on any of the COD's. Do you not just level up to it?
Once you finish level 70 you'll get an option to enter prestige mode. If you enter it then you'll start back at level 1 and you can go to 70 again. You can do this ten times. You get a different emblem by your name for every prestige.
Once you enter prestige there are extra challenges available too...