Hello! Welcome to LQ
How do I drive a car? The answer is, "Is it stick or automatic?"
How do you connect to the internet? Is it DSL, dial up, ISDN, Cable, fiber, DHCP, static, wireless... What kind of a connection do you normally use?
As for your ISO info, it depends. Did you burn the image
to the disc or the file? What I mean is that an ISO image is meant to be burned as an image to the disc. In windows something like Nero would work, it has an option to burn ISO images. IF you just burned the file (Mepis.6-something.iso) to the disc, so that when you put it back in and you pull up the contents and it just lists that file, then it's basically a "dud". You will need to reburn it as an image. From there, you boot up your system with the CD in the drive, tell your BIOS to boot from the CD drive, and the rest is documented well several times over.