I’m coming up to speed on MOSS and Bob Fox has a straight-forward 20 minute video on backup and restore for MOSS.   He shows how use stsadm and the UI.    It was a good overview for those coming up to speed on MOSS.  

http://video.msn.com/video.aspx/?mkt=en-us&vid=fa758139-898f-4e95-b7ba-9d43db3865bf&wa=wsignin1.0

Here is another link with great information on Technet.

http://technet.microsoft.com/en-us/library/cc262412.aspx

Steve