This article, among others, and Bulletproof Web Design, is where my head will be buried over the next few months as I revisit my CSS skills and improve my abilities.

This entry was published a year ago, but since a couple of people have
emailed me telling me what a great resource it has been for them I have
updated it some and am pushing it back to the front page for anyone
that missed it.
Learning CSS » Wisdump