There should be a fourth disk in the set - Printing Tools. Not absolutely necessary, but if you want a truly "stock" install, it should have that disk to install off of.
But to reset, boot from the "System Tools" disk or Utilities 1 disk, launch "Apple HD SC Setup", format the boot disk. (Which disk it's on depends on which exact version you have.)
Reboot to the System Tools disk, and run the installer. If you don't have the Printing Tools disk, choose a minimal install for your system and don't pick any printers.