If you own an iPad and enjoy the format of the interactive HTML book Smooth CoffeeScript, you might take a look at CoffeeScript: An Interactive Reference by Trevor Burnham. At just 15 pages, it is priced at $4.99. The thing that excites me is that it encourages you to code while you read.
For my upcoming book on Backbone.js and CoffeeScript, I am working on a subtle approach to interactivity that does not disrupt the flow of normal reading. Most readers say that they do not even notice at first that the code listings are embedded CoffeeScript editors. You can experience a prototype in this tutorial on helper functions with Eco (Embedded CoffeeScript templates). The current version of the format now uses wonderfully readable assertions from chai.js instead of browser alerts.