Building Secure ASP.NET Applications: Authentication, Authorization, and Secure Communication
Microsoft have released reference guide that presents a practical, scenario-driven approach to designing and building secure ASP.NET applications for Windows 2000 and version 1.0 of the .NET Framework. Download this guide as a PDF, here. It's a must read for any web developer/web architect developing ASP.NET pages/web services with .Net Framework. So cool !!!