I meant to blog this earlier but the page at http://www.microsoft.com/events/series/msdnnetframework35.aspx?tab=webcasts&id=live lists the webcasts for the .NET Framework 3.5. There are several 100 level webcasts on ADO.NET Data Services and WCF to help you get started along with some 400 level webcasts for those who want to go deep into the technology.