The challenge for a reference book like this is to be better the documentation that Microsoft provide - MSDN and the .Net framework SDK. My experience is that this book certainly achieves that.For example, today I needed to show the "save file" dialog and then write the contents of a text box to a text file. I know how to do that in VB6, but I hadn't done it in VB.Net before. I searched MSDN which gave me accurate descriptions of the menthods and properties of at least four classes for writing data to files, but I still had no idea which one(s) I needed to use.
I am sure the sample code I needed is somewhere in MSDN, but I hadn't found it after 20 minutes searching when I gave up and referred to this book. In five minutes I had found what I was after, my code worked and I was able to get on with my next task. That is what this book is for. If you want to learn about the new programming features in VB.Net (like polymorphism, delegates etc) this is not your book. But if you want help getting your .Net program to talk to anything (files, printers, active directory, browsers, TCP/IP Sockets, XML/XSLT or whatever) This book will be a valuable resource.
Just note that while this book covers ASP.Net and ADO.Net, if you work with these a lot you might want more depth than is provided here. I will be considering the Wrox "ASP.Net Namespace Reference" when it is released.