Previously, I posted about the free BPMN 1.0 poster available for download from ITPoster.net, and now the Business Process Technology Group at the Hasso Plattner Institute has published one for BPMN 1.1. Both provide a good quick reference; the BPT version has just the graphical object notation, while the ITPoster version also includes some patterns and antipatterns.
Also, check out BPT’s BPMN Corner, which has a number of good BPMN links, including Oryx, a web-based BPMN editor, and BPMN stencils for Visio and OmniGraffle.