Head over to Leanpub to grab a PDF version of this book
This book covers the nitty gritty of JAX-RS: a Java based standard (specification) for building RESTful web services. It covers JAX-RS 2.1 (the latest edition) and can be used as a cheat sheet or a getting started with JAX-RS style guide.
The contents of this book are divided into distinct sections which cover the bare basics, core components and some of the advanced framework features as well. Here is an overview