Debugging ASP.NET focuses on the various tools, techniques, and best practices associated with debugging ASP.NET web applications under Microsoft's new .NET platform. Brief descriptions of the problems with debugging previous versions of ASP are covered, as well as how the new features of ASP.NET can be exploited to their fullest to find and eliminate bugs quickly and easily. The book introduces changes to the code structure paradigm as implemented in the .NET platform, and how to structure ASP.NET code in this new paradigm to enable faster web application debugging.
This book is written by a guy that made a small company dedicated to programming with free tools. Thus, it tries to show how to debug ASP.Net assuming that you come from an ASP background and that you don't have Visual Studio .Net. So I don't think I have to tell you how much useless information there is in there. It even covers programmatic code tracing.
That doesn't mean it is a bad book, just useless for me. If you expect some wonderful debugging frameworks or code structure that would allow you to easily debug your applications, then this book is not for you. Not to mention that at the time it was written, Visual Studio 2005 was not out yet.
Bottom line: just a hands on approach and some Google when you meet problems will solve any problems that are solved by this book.