How to Learn AJAX - Asynchronous Javascript And XML

AJAX, also known as Asynchronous Javascript And XML, has taken the Web by storm and has dominated the Web 2.0 stage with it's flash-like features and awesome auto-generating effects. AJAX is not easy to learn. But there's a million text tutorials out there on the web on how to learn AJAX... but how good are they? Most are NOT worth the read. A lot of these tutorials are written by people who have little experience and are just looking for some more traffic to their websites in hopes of grabbing a few clicks to their advertisements.