As mentioned in this new post to his blog Jeremy Brown has put together a presentation he calls "A Conversation about REST", a discussion that centers less around the implementation of REST and more about the concepts needed to fully understand it.
REST is a set of principles and not a specification, so as such you have freedom in how to develop your API. This freedom can lead to confusion though, as it's hard to find concrete examples of its implementation. This presentation explained what REST is and also presented a variety of topics and questions you will certainly come across while implementing your API.
You can watch a video of this great presentation (as taken at a Club Ajax meeting in Dallas) here and can follow along with his slides off of SlideShare. He also links to a great image that gives a flow overview of the possible paths a REST request could take.