The Patterns & Practices Team have recently released v1.0 of the web services security guide (in PDF format) that shows how to make the most out of WCF. With end-to-end application scenarios, it shows you how to design and implement authentication and authorization in WCF. Learn how to improve the security of your WCF services through prescriptive guidance including guidelines, Q&A, practices at a glance, and step-by-step how tos. It's a collaborative effort between patterns & practices, WCF team members, and industry experts.
The guide has been released on CodePlex and is available for download.