Instructions
Pair the Controller
Attach the USB cable that comes with the PS3 to either USB port on the front of the PS3. Connect the controller to the USB cable.
Press the "PS" button on the center of the controller. The four lights on the shoulder of the controller will flash temporarily. When the flashing stops, the pairing is complete.
Disconnect the controller from the USB cable to use it wirelessly. If it needs charged, you can leave it connected.
Configuring the Controller
Start the game you intend to use with the controller.
Select the "Options/Settings" or similarly titled option on the game's main menu. You can also access the Options/Settings menu in-game by pressing the "Start" button.
Configure the settings to get the control options you want. Most games allow you to adjust the analog stick and motion control sensitivity, change the functions of buttons and disable the vibration.