The Crockford book is 4 years old now, is it still considered to be a good book to pickup? I've done JS off and on for a while, but mostly haphazardly (with an emphasis on the hazard). I'm looking to start doing some backbone.js and jquery and a book to help start off with it.
Despite being a small book you can ignore a good third of it, and I think his constructor pattern is out of date? but - it does do a good job of explaining the actually idiosyncratic thing about js - the whole prototype chain thing, and the scoping.
If four years would be enough to change a lot about the core JavaScript language, there wouldn't be a need for the book in the first place. It's still quite modern enough, and will be until a major EcmaScript overhaul is propagated and accepted by all common browsers…
It's not about modern web techniques, which is why it aged that well. For those, I'd personally recommend pulling apart some modern webapps or libraries, or reading modern tutorials. Usually you're somewhat outdated once your book reached its publisher… (Having said that, JavaScript Patterns is also pretty neat)