The first release of the LINQ beta code was distributed in September 2005 at the Microsoft Professional Developers Conference (PDC) in Los Angeles, and at the time of this writing, LINQ is still in beta. You can download the latest version of LINQ at http://msdn.microsoft.com/netframework/future/linq. As with any prerelease code, you should install this beta only on test systems, not on your production systems.
You can download both Visual Basic (VB) and C# versions of the prerelease LINQ code. Following the download and installation, you need to run the InstallVisual Studio IDE Support.cmd program. Remember that the LINQ project is all prerelease code and that it uses new keywords and syntax that are part of the next generation of the C# and Visual Basic .NET languages. Even Visual Studio 2005 doesn't fully support these new language enhancements. Therefore, some of theVisual Studio features such as IntelliSense don't support the new LINQ enhancements.
In addition to the LINQ code, Microsoft's Web site includes a LINQ forum at http://forums.microsoft.com/msdn/showforum.aspx?forumid=123&siteid=1. And Microsoft has also posted 101 LINQ samples (written in C#) at http://msdn.microsoft.com/vcsharp/future/linqsamples.