My copy of The Zen of CSS Design arrived this week, and I'm pleased to report that it is a beautifully, beautifully done book. (I might have expected as much based on the CSS Zen Garden website, but Amazon doesn't yet have a “search inside this book” preview available, so placing the order was a bit of a gamble in the end.)
So far I've just found time to read the introductory “View Source” chapter (in which the invariant HTML file for the project is examined in detail and its design rationale discussed), and have flipped through the subsequent chapters on “Design”, “Layout”, and “Imagery”. Your mileage may vary (be warned, the customer reviews on Amazon vary widely) but for my purposes this looks like it's going to have been a worthwhile educational/inspirational purchase — particularly taken together with Dan Cederholm's Web Standards Solutions, which I picked up at the same time.
My CSS education to date has been limited to thumbing through my now-slightly-outdated first edition of Eric Meyer's handy CSS Pocket Reference, diving the specs on the W3C site, surfing web design blogs and tutorial sites, examining source for pages with interesting layouts, and fiddling with macrabbit's excellent CSSEdit utility for Mac OS X. I'm hoping some new reading will help me expand my horizons ... maybe even learn a thing or two about the graphic design side of things.