The SP1 Beta does not include updated documentation for Visual Studio 2008, but it is all online.

You can start here: http://vs2008sp1docs.msdn.microsoft.com/en-us/default.aspx

A direct link to EF documentation is: Entity Framework

The tools documentation is not contained within there. Instead it is here: Entity Data Model Tools

The Astoria documentation is here: ADO.NET Data Services Framework

To me the most helpful thing is to see where it lives in the hierarchy so here's a pretty picture