JavaScript Step by Step by Steve Suehring is a good "plain-English" book for beginners. Although it lacks both breadth & depth, it covers topics that are relevant to current client side Web development. Out of the 19 chapters, 3 are dedicated to AJAX. The author's explanation of HTTP headers & how they can be manipulated with the XMLHttpRequest object is pretty interesting.
I found a couple of sentences in the book ridiculous
Obtaining an MSDN account from Microsoft will give you access to legacy products, including older versions of Internet Explorer, so that you can see how your site reacts to a visit from Internet Explorer 4.
IE4? Should anyone go out to please someone with a IE4 browser?
addEventListener() is defined as a "cross-browser (except for Microsoft Windows Internet Explorer) event handler method"
Now, that's a funny definition of cross-browser - excluding the most popular of browsers.
IE4, by the way reminded me of the first Javascript book, I purchased way back in 2000 - Pure Javascript. It lists every method and property of Javascript objects available at that point of time. At over 1400 pages, the book is so bulky no one may have read it from first to last, probably not even it's proof readers - it had quite a lot of errors and some of the snippets didn't run. I however liked the idea of having all possible methods and properties for ready reference. W3Schools which I discovered much later has an exhaustive coverage of Javascript too with great samples(except maybe this IFrame scrolling example). It remains one of my favorite learning resources.
