We've read plenty of Ajax guides by now. Beginning Ajax is one of the most sensible, patient, coherent, and comprehensible we've seen. It's not just well written and well presented: It reflects the growing maturity of Ajax development that has followed the early, hype-driven race to Ajax.
Chris Ullman and Lucinda Dykes open with a thoughtful discussion of what's new (and old) in Ajax, when it makes sense to use it, and when to avoid it. For example: Could your application benefit from constant, automatic updating, or partial page updates? Will Ajax cause problems for you in mobile applications or offline viewing? How do you know whether using Ajax will improve application responsiveness or worsen it? (Incidentally, if you're worried about broken bookmarks and Back buttons, the authors point you to a solution.)
You'll learn how Ajax integrates with server-side technology (the authors' techniques will work with any platform you choose). Now you're ready to dive into the heart of Ajax. You'll find clear and thorough coverage of using XMLHttpRequest (and its alternatives); extracting XML data, element, and attribute values; debugging and error handling; using XSLT and XPath; integrating external data and web services, and even using the JSON lightweight data-interchange format to streamline and accelerate your Ajax code. There's also a very welcome chapter on Ajax programming patterns. In short, this is all you need to go from Ajax beginner to Ajax pro. Bill Camarda, from the April 2007 Read Only