RESTful Web APIsBy Leonard Richardson, Mike Amundsen, Sam Ruby
Publisher: O'Reilly Media
Released: September 2013
This medium size-book is easy to read, because of it has good structured content, relevant real-life examples and simple terminology. The book doesn't require any specific knowledges, so it can be recommended to newbies as well as to experienced software engineers.
The book gives a detail overview of HTTP, before actual start dealing about REST services. Then it provides recommendations about handling collections and media over RESTfull API. Microformats and deep dive into the most powerful HTTP feature for REST API - are the parts that I like the most. Haven't heart about HTML metadata profiles, or special kind of rest for embedded systems? So, in this case you can lear a lot of fascinating things. Also, very important is "multilanguage" orientation of the book. It doesn't relies on REST API implementation in some specific framework or even language, instead of that authors describe common principles of writing services.
The book was split in 13 independent chapters. So, a reader can concentrate only on important topics and omit not interesting/actual topics. I believe it is quite positive about book. Personally, I'd prefer more practical examples, and less theory. However, it'd be really difficult to achieve without increasing book size in twice. So, authors decided to focus more on wide theory and you will need more investigation before staring using some of mentioned approaches as the result.