I stumbled upon this JavaScript Garden page.
It’s one of the best resources about in-depth JS knowledge IMHO. And if you wanna be a JS guru it’s a must read. It shows all the more why JS sucks though :) So many fugly syntax problems, non-intuitive language. Weird scope management. And what not… Just read it anyway.
This website is very reminiscent of a book I read, which I recommend reading. It’s called “Javascript: the good parts”.
http://www.amazon.com/JavaScript-Good-Parts-Douglas-Crockford/dp/0596517742