Finding CSS in MOSS

While developing custom webpart, we always wonder for which style sheet class to use.
And try to find out by checking view source of the default page.

Here is the link for
CSS Reference Chart for SharePoint 2007 (Microsoft Office SharePoint Server 2007 and Windows SharePoint Services v3) by Heather Solomon.

This is the wonderful post by Heather Solomon which helped me to solve my many GUI and CSS related problems.