Getting Started With OAuth 2.0, by Ryan Boyd, provides an introduction to the latest version of the OAuth protocol. The author starts off by exploring the origins of OAuth, along with its importance, and why developers should care about it. The bulk of this book involves a discussion of the various authorization flows that developers will need to consider when developing applications that will incorporate OAuth to manage user access and authorization. The author explains in detail which flow is appropriate to use based on the application being developed, as well as how to implement each type with step-by-step examples. Note that the examples in the book are focused on the Google and Facebook APIs. Personally, I would have liked to see some examples with the Twitter API as well. In addition to that, the author also discusses security considerations, error handling (what is returned if the access request fails), and access tokens (when are access tokens refreshed, and how access can be revoked). This book provides a good starting point for those developers looking to understand what OAuth is and how they can leverage it within their own applications. The book wraps up with a list of tools and libraries that are available to further assist the developer in exploring the APIs supporting the OAuth specification. I highly recommend this book as a must-read for developers at all levels that have not yet been exposed to OAuth. The eBook format of this book was provided free through O'Reilly's Blogger Review program. This book can be purchased from the O'Reilly book store at: : http://shop.oreilly.com/product/0636920021810.do