There are already 3 or 4 good books out on Silverlight 2. They range from the basics about "how to do Silverlight" to using Expression Blend and more. But this is the only book on Silverlight that deals 100% specifically with "data" - how to expose it, how to bind it, and so much more.
John Papa has a good reputation in the .NET community -- he blogs, has had a nice series of articles published in MSDN Magazine, he's a good presenter. And I know from his tweets that he spent a long time putting this book together.
Papa starts out the book with the almost obligatory chapter on the Framework, controls and especially the language enhancements needed to work with Silverlight - Automatic Properties, Object and Collection Initializers, Extension Methods, Implicitly typed variables, Anonymous Types, and LINQ.
In Chapter 2, the author gets into the nitty-gritty of Databinding with FrameworkElement, Dependency Properties, XAML Binding markup extensions, runtime binding, DataContext, and binding in Blend.
In Chapter 3, John covers the Binding Modes, Notifications, and implementing the INotifyPropertyChanged interface.
In Chapter 4, he moves on to binding to controls, Templates and Rows, Data Templates as Resources, List types, and Converters. Very well - rounded, and comprehensive.
In Chapter 5 you'll read about WCF, Web Services and Cross Domain policy files. Papa instructs us in how to consume services, how to perform asynchronous invocation, bindings, and much more.
Chapter 6 covers passing entities in WCF, using LINQ to SQL, Entity Framework.
In Chapter 7 we learn how to consume RESTful Services with WebClient and HttpWebRequest classes, including threading.
Chapter 8 is a comprehensive example of using Amazon's RESTful services with Silverlight.
Chapter 9 shows us how to create RESTFul services and introduces a new example project, "SilverTwit" - a Twitter client.
In Chapter 10, John covers Syndication Feeds including how to aggregate feeds with Silverlight.
Chapter 11 provides complete coverage of Silverlight 2 and ADO.NET Data Services, including using ADO.NET Data Services over the Entity Framework.
The book concludes with an ADO.NET Data Services Quick Reference, and coverage of how to debug with HTTP Sniffing tools such as Fiddler 2.
There is no question that in order to build robust, useful Line of Business applications with Silverlight, one needs to understand how to work with data in this new client platform. John Papa's "Data-Driven Services with Silverlight 2" provides a solid base of learning for both the new developer and the seasoned professional who are moving to creating applications in Silverlight. The coverage is well planned, detailed, and none of the important basics are left out. In addition, the downloadable source code provides an excellent sample codebase from which to launch your Silverlight coding efforts.
This is definitely a book you'll want in your "Silverlight Kit". I could say that it's the single best book on Silverlight Data Access, but the fact remains that it is the only book that currently covers this important subject in detail. It lists for $44.99 and comes with the O'Reilly 45 day free membership to the Safari online edition, as well as downloadable source code examples for everything. Search around, and you can find the book at online discounters such as bookpool.com for as low as $27.50 US.