Who is this book for?
You, if you want to learn Coffee-Script from the ground up. Maybe it is your first language or you know .Net, C++ or PHP. The book lays the foundation needed for complex web applications, game logic & algorithms.
If you already know some JavaScript then you might want to look at The Little Book on CoffeeScript and Eloquent JavaScript.
You can also cherry-pick topics; for example QuickCheck, Underscore, WebSockets or class inheritance.