Depending on your home set-up, it might be more convenient for you to connect your Xbox 360 to a computer monitor rather than a TV. If your monitor has more than one input port (e.g., two VGA ports or one VGA and one DVI), this makes for easy switching between your computer and the Xbox 360. In order to connect your 360 to a monitor, you need to purchase Microsoft's Xbox 360 VGA cable, which unfortunately is not included with your Xbox 360 console.
Connect your Xbox 360 VGA cable to your Xbox 360 AV port, then connect the VGA portion of the cable to your monitor's VGA port. Finger-tighten the connected screws to secure the connection.
Connect the AV (also called RCA) audio out portion of the cable to your audio system's Audio In ports. You need both a left and right (white and red) input to have audio for your Xbox 360.
Turn on your Xbox 360, monitor and audio system. Your Xbox 360 is successfully set up to work with your computer monitor instead of a TV.