Start with high-confidence xml & data formats books, then narrow by subgenre or adjacent topics.
Programming Web Services With SOAP
James Snell, Doug Tidwell
Programming Web Services With XML-RPC
Simon St. Laurent, Joe Johnston
Learning XML
Erik Ray
Java and XML
Brett McLaughlin, Justin Edelson
XML for Dummies
Lucinda Dykes, Ed Tittel
Beginning XML
Joe Fawcett, Danny Ayers
