Source: www.myvbprof.com
List of videos:
Creating the OR Mapping Classes
Query Set #1
Simple single-class (Table) queries
Query Set #2
Extension methods, navigating between classes, and query clause ordering
Query Set #3
Anonymous types and lambda expressions
Query Set #4
Master/Detail data binding
See more at http://www.myvbprof.com/2007_Version/LINQ_to_SQL.aspx