I have just posted an overview screencast about EntityDataSource to channel9. The EntityDataSource is the new ASP.Net Data Source that ships as part of the ADO.Net Entity Framework in Service Pack 1 of Visual Studio 2008 and .Net Framework 3.5. In this video you will get a quick overview of the EntityDataSource and see some additional features you may want to explore later.
If you want a step by step walkthrough of using the EntityDataSource, here is where you can find:
You can watch the screencast on channel9. If you'd prefer to download the WMV and watch it offline, you may do so here.