Reading this book, I was regularly (I don't mean sometimes) stopped my in my tracks because of the typing errors, style errors and layout issues. This book is marvel when it comes to a being a book editors' study material. You can annotate and correct about every page in this book. Obviously this is not published by an experienced publisher, trying to mainain a reputation for publishing serious and worthwile information.
That said, I must say that I learned from this book. Being ignorant about the way the Mobile world is organized, it gives you insight in what to do and what not to do when you consider building applications and services for the Mobile market. It doesn't really give you any design guidelines, but it does sketch the environment and comes with sound advice.
So, if you are really eager for this type of information, you can learn from this book. That is, if you are not put off by the writing and layout. What you cannot learn is how a publication like this is written, edited and layed out, unless you are studying to be a book editor, in which case it makes perfect study material...