I got an email (a few weeks back - sorry - trying to keep up ;) from a developer who wants to use jQuery but doesn't really know JavaScript first. Having to learn how to walk before you run - I was curious as to what folks recommend for the best way to learn JavaScript? I'll list out a few options here and I'd love for my readers to comment on what they would recommend.
For me, I initially learned via documentation on Netscape's web site. That was back in 96 or so, but the developer network has come a long way since then. Oddly they list out the reference before the guide - I'd definitely start with the guide.
The other big help for me was the O'Reilly book JavaScript: The Definitive Guide
Another book - although one that can at times be complex - is Object-Oriented JavaScript by Steven Stefanov. I reviewed that last year and made the point that it had quite a bit of good introductory material as well.
Another option are conferences. I had always assumed the jQuery conferences were for Ninjas only. (Ok, JavaScript Ninjas I mean.) And while the average technical level was quite high, the quality was excellent and I'd still recommend it for someone new. Just be prepared to take a lot of notes and ask questions. Of course, the excellent cfObjective that just ended also had multiple JavaScript sessions. I saw excellent ones from Ezra Parker and Elliot Sprehn that were both pretty darn enlightening.
Lastly - don't forget that all of this runs in a browser. If you've got a browser (and - um - you must) and a text editor that you have all the bare minimum tools you need. You may want to look at using Dreamweaver to help out - or the excellent Aptana editor as well.
Like most things - how you learn best is something you know. Books, online training, just playing, or a mix of all, figure out what works best for you and just make the time.