It is surprising to me how many companies are still not utilizing the powerful capability of content types in SharePoint. Just like every other capability in SharePoint, I believe in showing the power of it rather than just talking about it. So to that end, I have made the understanding and using Content Types video (created by Wendy Henry) available free on the site (it will be free until the end of this month). This video is for SharePoint 2007, but the concepts apply equally well in SharePoint 2010. Hope this helps.