Well third post based on InfoQ... Found free .NET and Agile books, you can download them below (regsitration required): Composite Software Construction Scrum and XP from the Trenches Agile Patterns: The Technical Cluster Domain Driven Design Quickly Scrum Checklists Enterprise SOA Adoption Strategies
If you need a great book on linq than i can recommend you the following book from microsoft - Introducing microsoft LINQ ( by Paolo Pialorsi and Marco Russo). It has some very details information regarding various syntax sugar and new features, posibilities and various flavors. In addition i recommend to read Mads Torgersen related post and wesdyer post regarding functional languages and syntax. hope you'll enjoy