I've just installed Debian Lenny and generally am impressed with how well things are auto detected and configured - so much easier than a few years ago - and in many ways easier than a Windows install where you have to constantly find 3rd party drivers to get things working.

 However getting wifi running was a bit trickier (largely because of FCC regulations  affecting licenses and default settings).

This document got me most of the way

http://wiki.debian.org/iwlwifi

Additional lines in /etc/.network/interfaces