Thank you for posting in the Apple Support Communities. I found some information that might help with transferring information between your computer and Apple TV. I found an article about Home Sharing that talks about what Home Sharing does and how to set it up:
You can use Home Sharing in iTunes 10.5 or later and on Apple TV to share the iTunes library and photos of any computer on your home network.
You can find the full article here:
If you are trying to setup Airplay from your computer, I also found some articles on how to set that up. AirPlay Mirroring lets you send what’s on your Mac screen to an HDTV wirelessly with Apple TV. If you are running Mountain Lion on a Mac compatible with Airplay Mirroring, you can share your whole screen using these steps:
If you are not running Mountain Lion, you can still use Airplay with iTunes and iOS devices following the steps in this article:
I hope this helps!