As a project manager, I use Scrum in my projects. The Guide to Scrum Body of Knowledge by SCRUMstudy provided a complete reference for the Scrum project I am working with. It is a very good book and extremely readable. I really liked sections on risk and quality. The tools mentioned in the processes were very helpful. I highly recommend this book if you are planning to implement Scrum in your organization. You can go through the first chapter available on