uhm... I didn't try Windows PowerShell until yesterday, but now I'm becoming addicted!!!
Some links...
Windows PowerShell on Wikipedia - a general intro, and some "fundamental" links.
On Microsoft's site, the main page for PowerShell (from here the link to the download pages - if you use XP sp2, here's the direct download link).
some Sample Windows PowerShell Scripts on Microsoft's site
and the CodePlex repository for Windows PowerShell scripts
Then a little article (on ThinkersRoom.com) on PowerShell customization, that introduces some interesting arguments through maybe "basic" yet well written. Read it.