This page will hold sites that I have used to understand and to reference Business Process Modeling. 

Site Name	URL (Web Address)	Description
Object Management Group / Business Process Management Initiative	http://www.bpmi.org/	This is the web page of the group creating the standards for this notation.  Check out: BPMN 1.1 Poster
Dive into  BPM	http://www.diveintobpm.org/	This site is a great tutorial for understanding BPM and how it works.