This is an awesome little book and a bit of a secret, probably because the title, color scheme of the cover and relative thinness make it look less like something to be seriously and more of a "design for dummies" book. Not at all - it's a short and excellent distillation of core graphic design principles down to a few short fundamentals.

An even shorter and online version of the same idea - the blog post on "how c.r.a.p. is your design?" on the role and usage of contrast, repetition, alignment and proximity:

http://www.thinkvitamin.com/features/design/how-crap-is-your...