Don Smith from the Patterns and Practices group has published an architectural and development guideline around the Web Service Software Factory specifically for WCF.

The Web Service Software Factory (also known as the Service Factory) is an integrated collection of tools, patterns, source code and prescriptive guidance that helps our customers quickly and consistently construct Web services that adhere to well known architecture and design patterns. The Service Factory provides guidance that addresses many of the challenges associated with building WCF and ASP.NET Web services and the components of a distributed application. These challenges include:

• Designing WCF and ASMX messages and service interfaces.
• Creating service contracts from existing WSDL and XSD files.
• Applying exception shielding and exception handling.
• Designing business entities in the domain model.
• Translating messages to and from business entities.
• Designing, building, and invoking the data access layer.
• Validating many aspects of the service using code analysis.
• Applying message-level security to WCF services.
• Planning for the migration to WCF.
• Applying message validation.

Find it here: http://msdn.microsoft.com/servicefactory