Welcome to LQ!
To burn an iso to DVD in a terminal:
/usr/bin/growisofs -dvd-compat -Z /dev/hda=slackware-10.1-DVD.iso
Change /dev/hda to your drive, and slackware-10.1-DVD.iso to the
correct path and name of your DVD iso image.
That was assuming you have a Linux distro to use.
If only Windows, just read the instructions at the Linux ISO