I've been putting together a text on ScriptUI, to a large extent to clear up things for myself (hence the title!). It's an introduction to ScriptUI, much of it very basic, here and there going into some detail. It's not a finished product, and comments, suggestions, and corrections are welcome. If you're interested, you can find the PDF file here: http://www.kahrel.plus.com/indesign/scriptui.html
Peter