I'm learning CSS (came from print). People keep telling me to look at CSS Zen Garden. It's from 2003, is it still useful, or are the techniques out of date?
Still useful, maybe more for the idea than the code. The point is that the same HTML can look completely different with only CSS. Look at the designs, then open the CSS and figure out how they did it.
Some of the old techniques are hacks you don't need now (box model hack for IE5). But most of it is fine. Then read the A List Apart articles: Sliding Doors, Faux Columns, In Search of the Holy Grail. That covers the basics.