The STSADM utility is a very powerful friend of a SharePoint admin. Watch this video to learn how you can use this utility to back up SharePoint sites

SharePoint out of the box does not contain the functionality to archive deleted sites. Use the Site Delete Capture feature made by available by Microsoft IT team on CodePlex to implement the site delete capture functionality.

This video walks you through obtaining this component, installing it and how to use it.

This video shows how entire SharePoint Sites can be backed up from one location and then restored at another location using SharePoint Designer 2007.