We’ve got apps, and we’ve got chms. Well, more specifically, a chm for Silverlight 5 beta.
To start, you can check out what’s new for Silverlight 5 beta. In addition to the new 3D support, there are many great additions to Silverlight for the SL5 beta release.
Next you will probably want the Silverlight 5 Beta Tools for Visual Studio 2010.
Last but not least, get the Silverlight 5 CHM.