The Back of the Napkin: Solving Problems and Selling Ideas with Pictures by Dan Roam (Portfolio).

A number of books have offered readers advice on different ways to use pictures, drawings, and charts to communicate complex ideas -- among them, Presentation Zen by Garr Reynolds, Slideology by Nancy Duarte, and the light-hearted Indexed by Jessica Hagy. This book, written by the founder and CEO of a Bay Area consulting firm called Digital Roam, rises above the crowd by treating visual thinking as a serious subject for managers. Roam's "Visual Thinking Codex" on page 141 -- a chart of doodles that helps you express the various stages of problem solving -- is the book's coup de grâce.