Instructions
Turn the PS3 off and connect the USB cable that comes with the system into any of the USB ports on the PS3. Connect the opposite end of the USB cable into the USB port on the top of the controller.
Turn on the PS3. Press the "PS" button on the center of the controller. The lights on the shoulder of the controller will flash and stabilize, indicating the pairing is complete.
Disconnect the controller from the USB cable and repeat the process with the remaining three controllers.