Here is one really nice tutorial in which Mark Wilson-Thomas demonstrates how to build a simple data forms application using Silverlight, VS 2010 and WCF RIA Services.
The final release of Silverlight 4 Tools for Visual Studio 2010 has recently shipped. Silverlight 4 Tools brings together Visual Studio 2010, Silverlight 4 and WCF RIA Services 1.0. This great combination of runtime and tooling makes it easier than ever to build LOB applications using Silverlight. In this walkthrough, I'll demonstrate this by using the Silverlight 4 tools to create a simple master-details product catalog application that reads and writes data from a SQL Server database.