Given how much time I spend at a whiteboard, I've often contemplated how to more effectively use that tool. A really well drawn diagram, particularly if it's accompanied by both a good analogy and a good example ends up hitting nearly all of the learning styles in a given room.

The Back of the Napkin was recommended to me as a really good book for how to improve whiteboard diagrams. That recommendation wasn't ill-founded. This approach gives a nicely structured system for how to diagram most common business situations. By focusing on the who/what/when/where/how much types of questions, you clarify your own thinking as well as ending up with things that are fairly easy to draw out.

Fortunately, if you're concerned about your ability to draw, this book should help to alleviate some of those worries. That's because nearly everything he shows could be drawn by a typical elementary school child. So, "I can't draw" is not a reason to avoid drawing in this kind of context.