JavaScript Newbie Seeks Guidance

[jswebdev]

I'm new to JavaScript, but i'm already at an intermediate level w/ PHP and i've built a few web applications w/ PHP / MySQL. From what I've read, I guess i'm not your typical learner in the sense that i went to PHP before JavaScript, but so it goes. I suppose there are no rules that one should come before the other.

anyway-- i've only just begun to do some javascript tutorials after learning a bit of the .js fundamentals from the Core JavaScript Guide at MDC. i'm not even sure that the Core Javascript Guide was the best place to start for learning JavaScript, but it seems like a decent overview, if nothing else-- and it's a credible source. but, if one were to ask me "what do you find useful about javascript?", i wouldn't have an answer because i really don't know of the practical applications, or really any applications for that matter-- other than pop-up windows, and visual/ display tricks, etc.

however, what i've read so far at another resource where i've found some tutorials -- in particular, the Tabular Data Control sounds quite useful. i'm looking for more resources regarding the TDC and Firefox.

also, if you know of any good places for a person in my shoes to start off on the right foot w/ learning JavaScript, its practical uses, and / or some good tutorials, etc., please tell me where to look for the best info. thanks!!