I recently discovered 2 good web sites that provide good JBoss knowledge :

• Master the boss : especially with articles with jBPM/JBoss ESB integration, jBPM best practices and JBoss AS tuning (a little bit outdated by the way, but still a good resource).

• Enterprise BPM blog : blog by a Redhat engineer involved in jBPM and WS-BPEL jBPM implementation. It has also links to other jBPM related sites.