1. what Lightning said

2. definitely use source safe of something like it

3. we do 3 kinds of documenting
1) in the code to allow other developers what's been changed and where
2) in source safe in the comments section
3) in an external doc that goes out to customers so they know what's been changed

4. if you're asking about source code, it strictly stays in-house, we ship new dll's for minor fixes and full installs for major fixes/modifications