look at this bunch of samples: http://msdn.microsoft.com/en-us/vcsharp/aa336746.aspx and here: http://weblogs.asp.net/scottgu/archive/2007/05/19/using-linq-to-sql-part-1.aspx
This isn't an answer. Please consider editing your qusetion to be *much* more specific. What exactly don't you understand? How much *do* you understand?