Adam Bien's Weblog
Useful Catalog of JavaEE 5-7 Schemas
This useful site: http://www.oracle.com/webfolder/technetwork/jsc/xml/ns/javaee/index.html lists all popular schemas for JavaEE 5 to 7 version.
However, XML deployment descriptors are rather unusual in JavaEE 5/6/7, so if you are using the reference site above frequently it may indicate a slight over engineering :-)
See you at Java EE Workshops at MUC Airport!
Summer Workshops: From Java EE 7 Bootstrap and Effective Java EE 7 to Java EE 7 Architectures