LINQ and C# 3.0 Articles and Samples

LINQ: .NET Language Integrated Query

By Don Box, Anders Hejlsberg

LINQ to SQL: .NET Language-Integrated Query for Relational Data

By Dinesh Kulkarni, Luca Bolognese, Matt Warren, Anders Hejlsberg, Kit George

.NET Language-Integrated Query for XML Data

By Michael Champion

The .NET Standard Query Operators

By Anders Hejlsberg, Mads Torgersen

Overview of C# 3.0

By Anders Hejlsberg, Mads Torgersen

Orcas Beta Samples

(Above link will always point you to the updated sample)