FaceTime is in Lion (OS X 10.7.x) and is in the Applications Folder and tends to have the icon Carolyn posted in the DOCK.
For Snow Leopard the later OS X updates will have added the App Store to the Applications Folder and the DOCK for you
You can then use this to download and install FaceTime on a Snow Leopard computer.
On a Mac you need to have an Apple ID that you are will to have used my FaceTime and need to enable that part in FaceTime (based on the Apple Document you were reading)
I actually use a different ID on my Macs to the one I use for these Discussions and my iTunes account.
Please, if posting Logs, do not post any Log info after the line "Binary Images for iChat"
iMac 2.5Ghz 5i 2011 (Lion 10.7.3)
G4/1GhzDual MDD (Leopard 10.5.8)
MacBookPro 2Gb (Snow Leopard 10.6.8)
Mac OS X (10.6.8),
"Limit the Logs to the Bits above Binary Images." No, Seriously