If you have downloaded our latest version you should have a C# examples executable under the Examples.CS folder in your Telerik installation directory. The link should be something like this:
C:\Program Files\Telerik\RadControls for WPF Q2 2008\Examples.CS\Telerik.Windows.Examples.exe
Once you have started the application click on the GridView example and you will see all the examples that we have made showing RadGridView's functionality.
Hope this answers your question. Looking forward to hearing from you again.
the Telerik team
Check out Telerik Trainer
, the state of the art learning tool for Telerik products.