Ah, a perfect combination of two things that I love: well-designed flowcharts and proper image crediting! The internet may seem like a free-for-all, but posting uncredited images can land you in a legal scuffle (not to mention that it's bad manners). Most of my article images are either public domain (found through Wikimedia Commons) or stuff that I've made myself. Otherwise, I add credit, just like I'm about to do right now.
Lovely flowchart via swissmiss.