I just received a mail with free E-Learning courses about Longhorn Server Beta 3, these courses are free for a limited time.
This online learning collection of five clinics introduces the new features and functionality in Windows Server "Longhorn." The courses cover server virtualization, security and policy management, branch office management, centralized application access, and server management. You can take the entire collection or just the courses that interest you.
Click here for the complete Microsoft Learning Resources for Longhorn : http://www.microsoft.com/learning/longhorn/default.mspx
Details on the free elearning:
Collection 5934: Introducing Windows Server Code Name "Longhorn" (Beta 3)—Free for a limited time!