As with most O'Reilly Nutshell books, this book is more a reference than a coder's primer. Unlike most, however, it is a bit lacking on how to code in the language.This is not all bad. The small size makes this a very useful book for the experienced coder to carry on client sites. The reference material is quite thorough and easy to navigate. It is this reason, alone, that added this book to my library.
If you are trying to learn VB.NET, I am not certain this book is your first choice. Of course, if you have purchased other O'Reilly titles, you are already familiar with this.
If I were to pick one audience for this book, it would be the VB programmer who was looking for a way to upgrade to the new VB .NET language. The appendices, esp. A and F, will help them move into the new technology quickly.