Now, on the other hand, if you don't yet know Javascript and you're trying to use jQuery, I would suggest learning the syntax and semantics of the language first. But if you know Javascript, then jQuery is trivial.
In that respect, I think maybe the biggest value in this book is the Javascript overview at the beginning. Too many people try to use jQuery without grasping its foundation.
http://productsearch.barnesandnoble.com/search/results.aspx?...
23 books - about 18 of which look to be entirely about jQuery, many of them very recent (this year or new editions this year), and at all levels.
I often go looking for the wrong thing. I'll think "In Ruby/plain JavaScript/C/whatever, I'd achieve X by doing Y and then Z" and then look for jQuery's equivalents to Y and Z, rather than doing it the easier and conventional jQuery way.
Books are good at relaying the thought processes of experts rather than the function by function material that, yes, a reference site provides a lot better.
For a slightly convoluted example, let's say I have a little JavaScript and DOM knowledge and am a few days into using jQuery without following any serious tutorials or books. To change the code within an element I might try something like $('#whatever').innerHTML = 'whatever' rather than the more jQueryesque $('whatever').html('whatever') - a simple example but it can get a lot more elaborate than that.
However, it's definitely a case of different strokes for different folks. You might be able to pick up on the idioms and nuances of new libraries and languages without much guidance, but books like Rebecca's can provide a much needed "guided tour" for some people nonetheless.
All of the above is why I wrote Beginning Ruby despite the existence of the venerable Pickaxe. The Pickaxe is an awesome reference book with a relatively weak tutorialesque set of chapters tacked on the front. My book caters to people who want to learn in a more linear, narrative fashion (and, to be fair, has a relatively weak reference section tacked on the end ;-))
I learned a lot of bad habits this way - because there are always two (or more) ways of doing things, and one of them is usually better than the rest. I just figured out that I was doing those things wrong when reading the book.
Case for example: Increasing Performance with Event Delegation - http://www.rebeccamurphey.com/jqfundamentals/#N20DAA
When I started learning jQuery, I scratched my head over this issue - I assign event handlers for a class, but they don't apply for elements that were added later to the DOM. Had the aha! moment when I figured out what was happening. The best solution I could find was to keep on assigning the event handlers whenever I added something to the DOM.
It served me well but Rebecca just taught me that there is something called $.fn.live and $.fn.delegate designed solve exactly this problem. This I would not have searched in the docs because I did'nt know that there existed something to solve this; and even if I thought there did, I might not have been able to frame the right question.
And there are lots of other gems that I picked up from this book.. jQuery really needs this. Especially for beginning developers who discover the power of jQuery - it helps them learn the right habits from the get go.
And the book is very concise and informative that the author deserves great praise for an excellent job.
Thanks, Rebecca Murphy!