Here are a few links that might help if you are just getting started with Oracle BPM.
Oracle Product Management's Oracle BPM main page
Oracle Technical Network's (OTN) Oracle BPM forum - You can ask any type of question about Oracle BPM on this forum.
Oracle BPM Documentation - Start here if you are using Oracle BPM 10g. There is a tutorial on this page that helps some people get started. The tutorial is confusing in a few places, so be sure to ping this forum for help when/if you need it. I will add an entry on this blog that will help you work around the errrors.
Oracle BPM PAPI (API) Documentation
Oracle BPM Software download page
Oracle BPM Software configuration matrix