Understanding Comics
Scott McCloud (1993).
http://scottmccloud.com/

For me, this is just one of the most influential books (on the same plane as Ways of Seeing, Berger) about art, visual culture and our understanding about how visual representation works.

Within the vocabulary of comics are the use of icons and the idea of "Amplification through Simplification". We are designed (or programmed?) to read and understand line drawings in a way that picks out the meaningful parts. In some ways, we can't help but to read faces from a circle, two dots and a line - like for those that can read; words cannot be unread. Rather than shaped lines; letters become words and sentences and so, as soon as you can decipher the code - you HAVE to read what is there. And there is a similar concept with cartoons and icons.

Simple line drawings, or cartoons, are simply vaccums for us to be able to see ourselves within.

Image from: http://blog.visualmotive.com/2009/understanding-comics-with-scott-mccloud/

More links and posts:
http://laurenericksondotcom.wordpress.com/2011/09/22/scott-mccloud-understanding-comics/