There are lots of places to learn how to hack together code to make things happen in the browser, or places where you can learn the basic vocabulary of programming. Here, you will learn the very grammar of the best practices of programming, including how to make your code object-orientated. Even how to start writing your own libraries, or, at least, not to be freaked out at the idea of writing your own libraries.
It is well written and concise. The trade-off here is that it is rich. Very rich. I've re-read it twice and I'm still finding things I need to commit to memory - not a lot of space is spent revising/reinforcing. The author warns you about this in the introduction though!
Only after a thorough grounding in the better aspects of the language does it move on to tell you about techniques you can use in the browser - about 2/3 of the way through. I didn't have a problem with that but I can understand how it might aggravate some readers.