Following links should help you get jump started pretty quick since quite a few of them are video tutorials-
1)http://www.oracle.com/technetwork/middleware/bpm/learnmore/bpmwebinarseries-361340.html (Collated
BPM Webinar)
2)http://andrejusb.blogspot.in/2010/10/initializing-oracle-bpm-11g-process.html (Initializing Oracle BPM 11g Process Payload from Oracle
ADF 11g)
How ADF BC and BPM Payload Interact
3)Building a sample BPM Process http://www.oracle.com/webfolder/technetwork/tutorials/obe/fmw/obpm/11g/r1/firstProcess/firstprocess_obpm11g.htm