I wanted to mention a new resource for web designers that has cropped up in the form of xheight.co.uk (mostly because I just published an article there). While still in the begging stages it's proven to be a frequent stop for me in my browsing; the articles penned here are lucid and, speak on the theory of web design. It comes as another of David Bushell's creations, and so far, every post I've read has been chock-full of impressive web. You should check it out, and grab the RSS feed for your reading pleasure. Make sure to read my article, and then browse through more like it!
Also, keep an eye out for an addendum to my article on CSS Tabs, giving an explanation and tutorial of the CSS :target class.