Torrents

An ISO is an image file of a CD. You can either mount it on a virtual drive, or burn it onto a blank CD. I like Alcohol 120% myself, but that's only a 30 day trial unless you get a cracked version. It allows you to create up to 6 virtual drives to mount image files to, which can be pretty handy. It also has the ability to burn CDs/DVDs and such.

If you need any more specific help just lemme know.