Java Compute node in WMB

http://www.ibm.com/developerworks/websphere/library/techarticles/0605_crocker/0605_crocker.html

My SOA mindmap

open source soa book

http://www.opengroup.org/projects/soa-book/

websphere Message Broker

websphere message broker is used to mediate between various applications and handle message routing and message transformation from source / originating system to endpoint / receiver application.

IBM website has a very good  quick tour which is very useful for beginners 

http://publib.boulder.ibm.com/infocenter/wmbhelp/v6r1m0/index.jsp

For a brief technical overview refer below

http://publib.boulder.ibm.com/infocenter/wmbhelp/v6r1m0/index.jsp