I’d say the best way to get the black belt in javascript is to keep hacking on it. There’s so much javascript noise out there it’s hard to find any good online references (and the mozilla ones are woefully neglected).

The best book I have is the O’Reilly ‘Javascript the definitive guide’, the book with a Rhino on the cover. It’s got a lot of DOM specific stuff in there, but the core javascript description is pretty good (as well as being a good reference).

Hope this helps! I’m going to keep publishing the ninja-foo articles until I reach my own sad brown-belt limitations.

I read some of your “javascript magic-ninja-foo” series and increased my js belt to a high blue belt. Have you found other good material (online or books) about OO Javascript? I’d like to become a full black belt javascript ninja.