Some WCF resources

WCF Developer Center on MSDN – it all starts with the MSDN Dev Center
WCF Community Site – tons of samples, tutorials, white papers, and more!
WCF Architecture Overview – high-level overview of WCF architecture and key concepts
WCF in the .NET Framework 3.0 SDK – WCF SDK reference
Introduction to Building WCF Services – a great intro article to get you started

Thanks to Ron Cundiff for above links.