The book is availiable for free as a pdf at http://www.infoq.com/minibooks/scrum-xp-from-the-trenches (registration required).
I've got the paper version from The Book Depository.com
This is a very straightforward book about Scrum. I would say that it is a very good starter for learning the basics of Scrum. This excerpt from the foreword by Mike Cohn describes pretty well the spirit of the book :
"Instead, Henrik jumps right in and immediately begins describing how his team manages and works with the product backlog."It gets down to the point, with many practical examples from his experiences with scrum. The book is pretty quick to read, only 125 pages. No "I've got no time to read" excuse for this one!
I really enjoyed the reading, and I suggest it to everybody that wants to know more about how to use Scrum on a daily basis.
I will probably add to my pile of "to read" books the other title from Henrik Kniberg : "Kanban and Scrum - Making the Most of Both".