XOM Site: http://www.xom.nu/
XOM-interest mailing list: http://lists.ibiblio.org/mailman/listinfo/xom-interest
Getting Started with XOM by Michael Fitzgerald, http://www.xml.com/pub/a/2002/11/27/xom.html
XML Made Simpler by Rogers Cadenhead, Linux Magazine, March 2003, http://www.linux-mag.com/2003-03/java_xom_01.html
nu.xom.samples package has simple example of many XOM features.
This presentation: http://cafeconleche.org/slides/javapolis/xom/