This is a great, easy-reading book for who wants to get the feets on network programming with .NET.
It covers the basic you have to know about networks and network protocols and then covers how to work with that on .NET.
The thing I like most on this book is that they loose almost no time with the common-places of distributed apps with .NET (the ones that every other book will cover, such as remoting and web services). The book covers really how to use TCP, UDP, and application level protocols such as HTTP, FTP, SMTP, POP and other.
Other aspect is that this book is really easy to follow and after you start you can't stop reading. I've received it on a friday night, so, I've consumed (devored) it on the weekend and I believe I would read it again...Great reading.