"if he decides to try Linux, would you recommend downloading and burning to a disk, or going somewhere and buying it on a disk. In a search I see RedHat, I see Linux.org, linux.com, linuxsoftware.org, linux.softpedia.com etc."

I'd recommend downloading Ubuntu and burning a CD. When you install it, it will set up an update link to an Ubuntu repository on the web, and via that you will be able to install updates and lots more software not on the CD.

Other distributions do this too, but Ubuntu (a) uses Debians's packaging system which is better than most of the others and (b) is pretty strong on hardware detection and user-friendliness.