I spent a few hours yesterday putting together the first segment in a new online video series that will demonstrate how to use different XML parsing APIs built-into the .NET framework including the XmlDocument, XmlTextReader/XmlTextWriter, XPathNavigator and XmlSerializer classes.  The first one titled "Using the XmlDocument Class" can be found here:

http://www.xmlforasp.net/CodeSection.aspx?csID=113

This video segment demonstrates some XmlDocument class fundamentals including how the Document Object Model (DOM) works, parsing RSS feeds, filtering with XPath, and editing XML.