http://www.cites.uiuc.edu/security/antivirus/bios.html (or here)
http://www-mdp.eng.cam.ac.uk/CD/bios.html
http://www.peacefire.org/bypass/booting-from-cd-tutorial/
http://www.hiren.info/pages/bios-boot-cdrom
https://help.ubuntu.com/community/BootFromCD