How to sell Macs

From The_Sellery_wiki

Macs must be reset to the state they were in after the installer first runs

For Mac OS X v.10.4 (Tiger) and earlier

• If you have the restore disc(s):
  • How to reset a Macintosh to boot to a clean and fully updated installation (Tiger / 10.4 and earlier)
• If you do not have the restore disc(s):
  • How to delete existing user accounts on a Macintosh and have it boot to the New User Setup Wizard (Tiger / 10.4 and earlier)