Apple TV (2nd generation) - Manual (Page 17)

Chapter 2 Configure. 17 Chapter 2 Configure.
If you don’t connect using DHCP, you may need to enter your IP address, subnet
mask, router address, and DNS address.
To complete the network connection, follow the onscreen instructions.
Connecting to iTunes
To access the content in your iTunes library on Apple TV, you need iTunes 10.2 or
later installed on your computer. For a complete list of system requirements, see
“Software and Accounts” on page 10.
Updating Your iTunes Software
You can update to the latest version of iTunes.
 On a Mac, use Software Update to update to the latest version of iTunes. To use
Software Update, choose Apple () > Software Update.
 On a Windows-based computer, go to iTunes Help to update to the latest version
of iTunes. Open iTunes, and then choose Help > Check for Updates.
Setting Up Home Sharing
After you set up your network connection, you need to set up iTunes and
Apple TV to share the contents of your iTunes library. Use Home Sharing in
iTunes and on Apple TV to share the iTunes library of any computer on your local
network that has Home Sharing set up.