Some of these sites on REST were helpful to me:

http://www.ryandaigle.com/articles/2006/08/01/whats-new-in-edge-rails-simply-restful-support-and-how-to-use-it

http://nubyonrails.com/articles/2006/10/09/peepcode-rest-basics

http://scottraymond.net/

http://podcast.sdruby.com/2006/10/3/episode-009-rest-with-rails

http://www.loudthinking.com/arc/000593.html