When you think about the important data you would want to back up should your PC fail, a big part of that has to be email and contacts. That's the "stuff" right there.
With your contacts, a great way to keep your Outlook (assuming you use that program) or even your Mac Address Book contacts handy in spite of a major PC crash is to use Plaxo (www.plaxo.com). It's free and as simple as downloading some software and setting up your account. The rest is basically automagic, if you will.
But what about email? The other day my mom's PC crashed and she lost it all. I had her going on Plaxo so her contacts were easy to restore. But all her email was gone. Bad!
I've since been trying to noodle out the ideal back-up situation for my parents as a result, and they were all a bit too complex for my folks. They don't want to have to monkey around with external drives and all that sort of thing. What a hassle! So it occurred to me the other day that there was an easier solution.