Keith Brown has published a very interesting guide to Windows Security - the twist is that it's available both as a convential book and here as a wiki. For those of you who are not familiar with the concept of a Wiki there's a good defn & explaination here.

The book covers a wide range of topics including Threat Modelling, least privilege, IPSEC, Kerberos, Confidentiality, Integrity and Authentication - a great reference for how to write secure code.