I you are looking for a good Javascript book Eloquent Javascript is for you. It is a free book readable on-line or you can dawnload on your ebook reader. In a lovely tutorial-style every characteristics of language are shown. Every sample code are downloadable from the same site. “This book is essential to understanding how to write Javascript applications. Not just the sort of everyday JS you might write in small snippets to support a site that is mostly driven from the backend, but the sort of modern, single-page application that today’s JS libraries support.”