If you are a beginner and want to learn about creating XML Web services from a very structured and detailed perspective then you'll want to look at this book. The authors present the material by building a Web service that will validate credit cards. Each chapter builds upon the one before it to give the user a good foundation in creating Web services using both HTTP and SOAP protocols. The development tool used to build the clients and Web services is Visual Studio.NET. I recommend using Visual Studio 2003 because the wizard for adding Web references is much improved compared to the one provided in Visual Studio 2002. The examples can be downloaded from the Microsoft site and are provided in VB.NET as well as C#.

Each chapter is presented as a number of steps that the user must accomplish to reach his/her goal. Some of the topics covered in the book are:

• Understanding XML Web services
• Developing XML Web services using Visual Studio .NET
• XML Web services and clients
• Building a SOAP client
• Building an HTTP client
• Data types in XML Web services
• Exception handling
• Debugging XML Web services with Visual Studio .NET
• Publishing and discovering XML Web services
• Advanced XML Web services
• State management
• The DataSet and XML Web services
• Caching and application events
• Securing XML Web services
• Custom SOAP headers
• Consuming XML Web services asynchronously
• Manually creating proxies

The authors present a fair and balanced approach to the current state of XML Web services and their use in the future. They are not afraid to criticize Microsoft if it is warranted. They are meticulous in their presentation and go the extra mile by providing a reusable template and explaining to the user how to make good use of it when developing XML Web services.

There are a few areas though where I wish the authors had been a bit more thorough, such as providing security for Web services. I feel that they did not provide alternatives to what is offered by Microsoft. I have seen examples of forms authentication for Web services as well as other novel ways to provide authentication and authorization. The other area that is completely missing in the book is the lack of any examples on the use of databases and ADO.NET to provide the Web service with data to return to the client. The authors have a nice section on DataSets, but they populate the dataset manually rather than from a database.