Mach3 vs Mach4

[birchy]

Now scroll down and there are 52 versions of Linux.

Yeah, I often laugh at that because the overwhelming choices puts off potential newbies. Lots of choice is great but it doesn't help the inexperienced.

Generally speaking, a bootable CD or DVD is the easiest. You download the O.S. as an ISO file and burn it to disk. Boot the PC from the CD/DVD and job's a good'un.

Forgive my ignorance, I don't know what a "hobber" is (EDIT: duhhh - just realised you mean a gear hobber)....If you're installing LinuxCNC, then you'll want their CD/DVD as it is a complete O.S. and software package. For anything else, Linux Mint is the way to go. It's newbie friendly and works straight out of the box. No need to install security packages (Norton, etc), Flash plugins, Java plugins, movie codecs, MS Office, etc..they're all pre-installed.

EDIT:
For your purposes, I think your friend is suggesting you install UNetbootin (which is the software used to create bootable USB sticks) BUT use the LinuxCNC ISO rather than one of those 52 choices! UNetbootin has an option for "Diskimage", so you'd need to choose that and point it at your downloaded image.