I don't do much DHTML as anytime I need motion I usually do flash but I had a small project for a media company that displays an html page inside the windows media player and when you click one of the buttons inside the page a different div (layer) is displayed.
I've always been annoyed by javascript due to the lack of an IDE or decent debugger, but I've been saved by venkman and JSEclipse, check out the venkman javascript tutorial here :
http://www.svendtofte.com/code/learning_venkman/setup.php
and the JSEclipse, javascript eclipse plugin that rocks too.
http://www.interaktonline.com/Products/Eclipse/JSEclipse/Overview
Cheers
Grant.
