Another good FlashMX XML tutorial

This one also gives good explanation. Better - it mentions several neat tricks in passing, for instance suffixing your XML object name with "_xml" informs the ActionScript editor that the variable is an XML object and the editor will provide a dropdown list of appropriate methods during editing. Sweet :-)

The FlashMX XML tutorial can be found here and it is hosted by actionscript.org. This too appears to be an excellent resource.