The patterns and practices team at Microsoft has been releasing betas of their new guide, Improving Web Services Security.

If you are a lead developer, or architect, and are working with web services (of any platform, but especially WCF) this should be required reading.

The guide does a great job first covering what you should care about, and look for with regards to security when designing web services.

The first section covers the fundamentals really well. What the threats are, an