Whenever I have worked with teams or Scrum Masters there has always been one book that I have recommended them to read. And now I'm happy to see that it has been updated.
Well technically the content of the book hasn't really changed but Henrik (the author) have added some comments to help your reading so the book is even better than before. I'm talking about Scrum and XP from the trenches and it is still free! Enjoy the read!