Over on the Irish TechNet security pages, they have put up some really good new training resources and references. They are organised from basic to expert and provide info on the planning, prevention, detecting and response phases of security implementation.

Specifically, it includes five great presentations on security from the event that Rafal Lukawiecki did recently on Identity and Access Management for a Heterogeneous Environment aswell as links to the 10 most popular security webcasts chosen by the TechNet audience (a good place to start!).

You'll also find a link to the Microsoft Security Assessment Tool, which you can install on your computer to obtain info and recommendations about best practices in security and other free security tools and downloads.