SharePoint User's group in cincy had a great speaker, Heather Soloman. Here are the links from the show.
Add-ons for FireFox HTML and CSS debugging and testing:
https://addons.mozilla.org/en-US/firefox/collections/dustin4792157/spbootcamp/
Note Pad ++
http://notepad-plus-plus.org/
Known public SharePoint sites:
http://www.wssdemo.com/livepivot/
CSS book recommendation:
http://www.transcendingcss.com/