How to Setting Up Apple TV
Apple TV connects to your TV through an HDMI port that delivers both audio and video.
Before you set up Apple TV,look at the ports on the back of your TV to make sure you have the right cables.
You can connect Apple TV to a high-defnition TV or home theater receiver that has an HDMI port,using an HDMI cable for both video and audio. You can also use an optical digital audio cable to connect Apple TV to a receiver for audio.
Important: Before you connect Apple TV to a power outlet,carefully read these installation instructions and the safety information in the included Important Product Information Guide
Taken from : manuals.info.apple.com/en_US/Apple_TV_2nd_gen_Setup_Guide.pdf