I've been working on a Manning Book called Multitouch on Windows with a subtitle NUI Development with WPF and Silverlight. I'm writing this book to accomplish two things. One, of course, it will teach you about developing multitouch applications using WPF 4 and Silverlight. The other, and perhaps more important, thing is to teach you about the new ideas and new ways of thinking required for creating natural user interfaces. There is a lot of talk about NUI at a high level, and a lot of interest in multitouch development and APIs, but there are not many resources out there to bridge the gap. This book does bridge the gap, and I hope it will give you everything you need to create multitouch application that live up to the potential of the natural user interface.
Today Multitouch on Windows became available under the Manning Early Access Program (MEAP). That means that if you pre-order the book, you get access to the chapters as I write them, before they go through the full editing and review process. This gets you the information now, and also gives you the opportunity to provide feedback, if you choose, and help improve the overall book. If you get the MEAP, then whenever I send Manning a new chapter or update an existing one, they will send you an email with a download link. When the book is complete, you'll also get the final e-book, or the e-book and printed book, if you choose that option. (There is a MEAP FAQ for more details on this.)
Right now chapter 1 "The natural user interface revolution" and chapter 4 "Your first multitouch application" are available to MEAP subscribers. Chapter 1 is also available as the free chapter, and you can download it right now! As this is an early look at the book, there are still a few quirks in the formatting and the illustrations, but all the content is there.

To go along with the book, I have also setup a website at www.HandsOnNUI.com. This site is about the book, what events I will be speaking at, and general natural user interface resources. Right now there isn't much there, but I have big plans for it. The only thing I will say now is that the site will soon be a complete multi-touch experience.
One last housekeeping note: Prior to yesterday, I had been referring to this book as Multi-touch development with WPF and Silverlight. After some conversations with the very talented people at Manning, we decided to update the title as it is now. I only mention this in case there is any confusion.