I have 50+ macs that I need to restore to factory settings to sell. What I think I'll do is install a fresh os on a disk I have, install iLife, and then clone it to each of the computers. I know there are some system files that you can delete to restore the computer to factory settings so setup assistant runs on the first startup, but I'm not sure which ones they are. I'll be working with Lion and ML. What are these files, and is there anything else I should know?