After writing the previous post that contained a collection of Linq To Sql links, I have found a few more which seem promising.
Enterprise Application Architecture with LINQ to SQL
An Example of a Multi Tier Architecture for Linq to Sql
Rick Strahl: Update to LINQ to SQL Business Object Wrapper Sample
Is the ADO.NET Team Abandoning LINQ to SQL?
Caching LinqToSql results with SqlCacheDependency