Instructions
Turn on your Xbox 360 wireless controller by pressing the "ON" button. Turn on your Xbox 360 by pressing the "ON" button on that device as well, which is located on the front of the console.
Press the "Connect" button on the front panel of your Xbox 360. This button is clearly labeled "Connect."
Press the "Connect" button on the top of your Xbox 360 wireless controller, located next to the expansion memory port. The green indicator lights on the front of the Xbox 360 controller (next to the logo button) will begin to flash. When these lights stop flashing, your Xbox 360 and your wireless controller will be synced.