Technically it is called the .NET Framework 3.5 Enhancements Training Kit, but without SP1 we wouldn't really be talking about this training kit now would we?  The kit is your one stop shop for an outstanding collection of

presentations, hands-on labs, demos, and other materials designed to help you learn how to use what's new in .NET 3.5 SP1, including: ASP.NET MVC, ASP.NET Dynamic Data, ASP.NET AJAX History, ASP.NET Routing, ADO.NET Data Services, ADO.NET Entity Framework, WCF 3.5 SP1, and the .NET Framework Client Profile.

I watched an internal webcast covering the kit and it's contents and it is very impressive.  I'll be spending some of my own time going through it, and if that is not a strong endorsement, I don't know what is! ;-)