one of the things about linux is that many of the distributions are free. and programs are free, eg. OpenOffice (compatible to some extend with MS office)is free. A company that uses such a distribution will be saving alot of $$ (for each PC you need a license for Windows OS, and Office... that will be quite some $$).
If you are not playing games and are just using windows to surf, email, and word processing, linux is definately more stable... without crappy IE crashing, viruses, spyware..trojans (viruses in *nix systems are seldom seen).
That said, linux distributions of today are definately different from that like 10 years ago. You can survive in linux without using the shell prompt, typing commands. I mean, how many people who started familarising themselves with Win98(to WinXP) still actually use the command prompt in windows ?
If there is a person who has never used a computer before, I would say it it is equally easy to learn linux as compared to windows (ok, perhaps one will want to start with a more user friendly distribution of linux)
1 thing to try --> knoppix distribution. Linux on a bootable CD, comes with lotsa of goodies(based upon the debian distribution). Load it up into your cdrom, choose your computer to boot form CD, and presto you have linux. If you like it you can install it to hdd.
if you want to try, try knoppix