If you’re interested in learning more about graphic design (beyond those first principles from Robin Williams)…
Smashing Magazine has a great series on design principles. The 5th (and I think final part) (Links to an external site.) just appeared – it has links to the first 4 parts. It covers different stuff than the Williams CARP principles – it focuses on applications of Gestault psychology and grouping.
I’ve also created a discussion on Canvas for people interested in discussing graphic design and learning more about it.