XML/AJAX

I've started a project of building a "Black Belt Family Tree" for Howard's branch of the WMAA (and possibly above?). It will be implemented in AJAX and XML (not just for buzzwords sake, but rather because AJAX is a powerful client-side tool, and XML is the native language of AJAX). To this end, I would also like to make the XML render nice in compatable browsers (I've heard IE cannot do this?) before attacking the harder problem of making a JavaScript client (it also may help me with thinking of the problem more visually. Here is the first XML file. Does anyone know any good online AJAX/XML resources? Any good dead tree ones?

Thanks!