Paul Aubin, famous author and one of the instructors at Autodesk University, has set up a web-based tool catalog that features content from his AU courses. You can access this by clicking the Add Content icon in Content Browser and choosing to add an existing catalog. Click on the Browse... button and type in the following URL as the location:
http://www.paulaubin.com/Public/AU_2004.atc . You can read more about this catalog in the Didn't get a chance to show this at AU thread in the Autodesk Archtitectural Desktop 2005 Discussion Group. I found the AU Logo Curtain Wall Style particularly interesting, and managed to reverse engineer it, with a little help from Paul.
Understanding the tool palettes is a must for anyone using Autodesk Architectural Desktop 2004 or 2005, as much of the out-of-the-box content is organized around having the typical ADT user view the tool palettes as the "one stop shopping" location for content. Paul's class provided a good overview of the basics and his handout went into even greater detail. If you get the chance to attend a future Autodesk University, you can not go wrong taking any course offered by Paul.