The TechNet Webcast: Hardening Windows Server 2008 Deployments with the Windows Server 2008 Security Guide (Level 200) is one of the top-rated webcasts last month. Also available as podcasts (audio only): WMA | MP3
splogscreen: if you are reading this on some site other than http://blogs.technet.com/tonyso, why not come on over to the original site?
Download the Security guide here. You may also find the security survival guide post useful, as well as the Learning Paths for Security.