I think the expression is "don't cry over spilled milk...", well when my son spilled milk on this book I almost cried. Why would you cry over a book you ask? There are many reasons. Not only does the book go into LINQ in depth (I know there is a C# in Depth book) but the authors cover all of the parts of the .NET framework that were created and needed for LINQ to function. In addition, all of the samples provided are both in C# and VB.NET. These samples are not your basic "Hello World" samples but useful reusable code snippets that get the point of the book section across.
The book starts of with an introduction to LINQ and the different versions of LINQ to xxx, more than enough to wet your whistle. The authors then go into the prerequisites of the .NET framework required, generics, anonymous types and lambda expressions. This chapter was so good I read it twice. The third chapter discusses how LINQ is made up. After this, the authors go in depth in describing the different types of LINQ, including LINQ to SQL, LINQ to Objects and LINQ to Amazon with useful examples.
This book will be a reference book on my book shelf. I expect to refer to this book constantly.