I'm very far from being an expert (somewhere a step above newbie is where I'd place myself), but thought I'd list off a couple of the resources that I use for learning about designing in the tangled interweb:
A good book that helped me wrap my head around CSS (cascading style sheets) is Web Standards Solutions: The Markup and Style Handbook. It's a very easy read and Dan's own site (www.simplebits.com) is another great resource to have in your RSS reader for tips. His new book (Bulletproof Web Design: Improving flexibility and protecting against worst-case scenarios with XHTML and CSS) is on my wishlist at Amazon and I've been planning to pick it up when my next 'big' web project comes along.
Pretty much any book by Eric Meyer would be good reading. I picked one at random.- For design ideas/inspirations I often head to one of these places: CSS Zen Garden (and the guy's site who runs it mezzoblue, the Movabletype Style Contest or Wordpress themes depending on what/if blog software being used.
- CSS Beauty, A List Apart, Godbit, Learning Movabletype
I'll add more as I think of them. What are some sites/books you use to help in your design escapades?