A good article on document approval, versioning, check in and check out.. lots of screen shots too.
http://itfootprint.wordpress.com/2007/08/01/140/
Source control is old hat to developers, but it’s a totally new concept for business users. I just have to remember that when I’m trying to explain this. 
Tags: check in, check out, document approval process, document library, SharePoint, versioning
