I have the original Model A1218 and have never figured out how to store content on the hard drive? Any advice?

If it's a silver AppleTV1, you need to be running iTunes on the same network as teh AppleTV 1 itself.

Next go to Settings>Computer on the AppleTV and add the iTunes library to the top line. To do this (I'm trying to remember!) you either highlight and select the blank line or there's a line saying add computer/itunes or similar.

When you 'add the itunes' AppleTV give a numeric PIN on screen - you then go to your computer which should be running with itunes open and select the AppleTv Device in the left panel in itunes, enter the PIN and AppleTV and iTunes are configured to sync.

When you click the device in itunes you have a variety of tabs - the first (you may or my not want to register the unit) will let you select automatic or custom syncing. Automatic fills AppleTV with what itunes thinks you'll want, I prefer Custom sync so that I can choose manually what goes onto it. Syncing can take some time.

AC

See this:

http://support.apple.com/kb/HT1143