Of those who see some interest in the results, some people, smart people, will ask for references to move forward. Most of the literature about agile, focuses on software development. We can find books about agile business, but these are generally a second step in the understanding of this culture.
So we need a book that is not too technical and lightweight. I proposed Agile Excellence to my colleagues and friends and considering their feedback, I highly recommend it.
I bought this book for myself because I was looking for a handbook focusing on my product manager position, and a book with drawings that allow me to explain agile principles easily.
The effort in story points, the detail level of a backlog, refining the user experience (UX), release plan, business value and managing multiple teams - they are all discussed. Greg Cohen chooses to use Scrum in the main chapters and talk about XP and Lean in the last one. I agree with the choice, because in my opinion this is simpler to explain to the general reader. Finally, with a small amount of description, he introduces waste elimination, presents the Process Cycle Efficiency with two efficient graphics, and mentions other lean principles.
At the moment, I really recommend Agile Excellence as a companion to Agile product managers and for those that need a tool to convince others about this culture.
280group : Agile Product Management Book
Club Agile Rhône Alpes : Vendre l'agilité aux décideurs ?