I truly enjoyed Back of the Napkin by Dan Roam, and since have been exploring visualization quite a bit. His book walks you through a 4 step process that helps you solve problems with pictures using 5 questions and showing it in 6 ways. For those who dread the whiteboard, it is an excellent resource to help pick up the pen. The more I practice the better I get. I can't stop drawing!
For those who would like to explore an encyclopedia of visual maps take a look at the interactive visual periodic table and the visual-literacy.org. For those who would like to delve into a variety of ways to interpret information.
