As Steve Stafford already mentioned, I have posted a tutorial on WikiHow based on a segment from my Autodesk University 2005 class "You Can't Do That With Revit!" The site is a collaborative effort to build the world's largest how-to manual. It's really a breeze to join (Free!) and start posting your own content. Sure, there's been debate over the validity of wikis in today's society, but heck - it can't hurt!
The how-to can be found at http://www.wikihow.com/Create-a-Freeform-Roof-in-Revit. Enjoy.