There are quite a few ways you could do this. I’ve honestly never done this, but I’ll try my best to point you in the right direction.
1. If you want to continue using Microsoft Office (the newest
version for Mac being 2008), it’s probably quite similar to how it works under Windows.
Here is a tutorial on Microsoft’s Web site telling how to do it.
2. If you would like to try Apple’s alternative to Microsoft Office (iWork), it’s quite simple as well. Here’s a
video from
this podcast that explains how to do it. All you’ll need to do (presumably) is export the contacts from Outlook and transfer them over into Address Book.
3. As Clayneal mentioned above, you could also try
OpenOffice.org (also available for Windows and many other platforms), although I was unable to find any Mac-specific tutorials, nor do I have much experience with it under OS X.