I got a copy of LINQ Quickly from Packt Publishing. Language Integrated Query (LINQ) is a new feature in Visual Studio 2008 that extends its query capabilities, using C# and Visual Basic. Visual Studio 2008 comes with LINQ provider assemblies that enable the use of LINQ with data sources such as in-memory collections, SQL relational databases, ADO.NET DataSets, XML documents, ect.
The book is written for .NET developers who want to find out exactly what LINQ is, waht it can do for them, and how to program with LINQ. The book has about 200 pages which are very good to read.
You can buy the book at www.packtpub.com . There is a 10% discount currently and free shipping for many countries.
The book covers all the basics behind LINQ:
I recommend buying this book as it is very easy to read and understand the technology behind LINQ.
For more details on LINQ have a look at the post from Scott Guthrie tagged with LINQ .
*) correct: LINQ comes with Microsoft .NET Framework 3.5.