Instructions
Turn on your PS3 and a controller, then navigate to the PS3 main menu.
Select the "PlayStation Network" icon and choose "Account Management."
Scroll down to the bottom of the list and select "Facebook."
Choose one of the three options in the following menu: "Share Trophy Information," "Share Purchase Information" or "Share Game Event Information."
Select the "On" option on the following page and then press "Confirm."
Input your Facebook user name and password on the following page and press "OK" to link your PS3 with Facebook. If desired, you can now go back and share the two options you didn't initially choose; you won't be prompted to enter in your Facebook user name and password again because your PS3 and Facebook have already been linked.