WordPress Custom Post Types Guide
One of the most anticipated features of WordPress 3.0 was the ability to add your own custom post types to WordPress, which allows you to display and categorize different types of content outside of the 5 native WordPress content types (i.e. Post, Page, Attachment, and so forth). The addition of this feature is a big step forward in making WordPress a full-fledged CMS, extending outside its normal use as a blogging platform.