In order to continue progressing my jQuery knowledge, I needed to have a solid understanding of JavaScript fundamentals.  This helps me comprehend what the concise jQuery code is doing behind the scenes.  Also, if I would ever need direct access to DOM elements rather than a jQuery wrapped set, I’d have the skills to do so.

There was a great JavaScript primer in the appendix of the book I’m currently reading, jQuery in Action, and I just wrapped up a lengthy video tutorial course on Lynda.com : JavaScript Essential Training.  I would recommend both if you’re new to JavaScript, as I was.