The information in this tutorial focuses on learning about JAX-RS and Jersey. If you are interested in learning more about RESTful Web Services in general, here are a few links to get you started.
The Community Wiki for Project Jersey has loads of information on all things RESTful. You'll find it at http://wikis.sun.com/display/Jersey/Main.
Fielding Dissertation: Chapter 5: Representational State Transfer (REST), at http://www.ics.uci.edu/~fielding/pubs/dissertation/rest_arch_style.htm.
Representational State Transfer, from Wikipedia, http://en.wikipedia.org/wiki/Representational_State_Transfer.
RESTful Web Services, by Leonard Richardson and Sam Ruby. Available from O'Reilly Media at http://oreilly.com/catalog/9780596529260/.
Some of the Jersey team members discuss topics out of the scope of this tutorial on their blogs. A few are listed below:
Earthly Powers, by Paul Sandoz, at http://blogs.sun.com/sandoz/category/REST.
Marc Hadley's Blog, at http://weblogs.java.net/blog/mhadley/
Japod's Blog, by Jakub Podlesak, at http://blogs.sun.com/japod/category/REST.
You can always get the latest technology and information by visiting the Java Developer's Network. The links are listed below: