This is a collection of LINQ to XML Resources that I've found useful.
Daniel Moth has a great diagram and explanation of the System.Xml.Linq namespace.
Hooked on LINQ's five-minute overview.
Microsoft's LINQ to XML Overview.
Hansel Minutes LINQ to XML podcast.
Joseph Albahari's excellent LINQPad utility can be used to visualize the workings of LINQ to XML. Plenty of samples in this application.
Scott Guthrie on how to build a custom RSS Feed Reader with LINQ to XML.
Typed XML programming by using LINQ to XSD.