In the case you will get a booklet on the side reading the code
If you pre ordered the hardened or prestige edition, you will get the code written on the challange coins and you will have to reedem it.
On PS3 You do this
1) Go on to playstation network section
2) Click on Account management
3) Then Reedem Codes
4) Type Your Code In And Enjoy (:
Hope i helped dude