Douglas Crockford: The JavaScript Programming Language
ontwik.com
ontwik.com
There are two more lectures, sort of a series when put all together:
Advanced JavaScript http://video.yahoo.com/video/play?vid=111585 (3 parts)
An Inconvenient API: The Theory of the DOM http://video.yahoo.com/watch/111582/992708 (3 parts)
Introduction to JavaScript and Browser DOM