I am a bit prejudiced, but I do think slim and Keef are a teeny bit too negative.
I did 2 installs last week for people, one of Mepis on a P4/512MB and the other of Kubuntu on a P3/800/512. Both installs went without a hiccough and I didn't have to provide any geek input at all. The P4 guy remarked, "Well, I could have done that myself...". All the hardware got picked up without problems and the only configuration in both was to fill in the email servers (which you'd also have to do in Windows). Note that with Windows you have to scrabble around finding all the CDs with all the drivers that you put away "somewhere safe". Current Linuxes have drivers for almost everything built in and it's only wireless cards that cause problems at times now.
Have to say that I've never, ever had to mess around with machine code to get any Linux (or Windows) install working. Sounds very odd, but then Keef does seem to find problems that nobody else has ever experienced.
The other consideration is that your Linux install will, as well as the operating system, install a whole slew of stuff that in Windows you'd have to install separately (Office equivalent, drawing programs, etc., etc.)
Yes, if you expect OpenOffice to be indistinguishable from MS Office you are likely to be disappointed. But it's very very similar and will do pretty much everything MS Office can (and some things MS Office can't). But if you're incapable of making even quite small adaptations to the way you work then by all means spend your money (MS Office 2003 Student and Teacher Edition/$129.99 - MS Office 2003 Professional Edition/$486.13).
Yes, Linux looks and behaves a little differently - if you insist on a free Windows clone then don't go there (though Linspire comes pretty close). But it's a bit like being given a Citroen and complaining that the indicators are in a different place from your Opel and that the dashboard doesn't look the same! And it runs well on quite modest hardware, which XP never did and Vista certainly won't (it's lightning fast on good hardware).
It ain't perfect and your PC still won't read your mind, but it don't cost anything and the freedom from worry about viruses, trojans, adware and malware without having to install expensive and system-borking anti-malware programs is a huge plus.
My picks for the newbie? Well, not Fedora, which isn't that userfriendly, but Mepis (free)-
http://www.mepis.org/ - or Kubuntu (free) -
http://www.kubuntu.org/ - or Linspire (modest cost).
My advice? Get a live CD and run it, see how you feel (just remember that the live CD will run VERY much more slowly than a proper install, especially on older gear).