what's the best way to discover it?

[omoi]

I was interested in beginning programming in Javascript but I was unsure where to start? Books? Websites? Where did you guys start?

[Nuvo]

One of the best sites I've found for this kind of thing is ALA (http://www.alistapart.com/), which covers many web design topics including CSS2, XHTML and EMCA Script (JavaScript, though EMCA Script is more correct as JS is based on the EMCA Script standard, as are Microsoft's JScript and Adobe Macromedia's ActionScript, though EMCA Script is a standard that was based on the early versions of JavaScript).
I learned what little JavaScript I know from seeing what code Ruby on Rails created when I used it's inbuilt AJAX features and from reading code from other scripts such as the post editor from SMF.