The first and the foremost, excellent resource for that is 'A LIST apart'. Boomer. Information about site structure, information you want/need to put there, CSS development tricks, tips and more. Read all that info (agree, it will take some time) and you'll be projected literally years ahead of what you know now about web design/development, especially if you are a beginner (as me ... hummm, when it comes about creative design, even site structure, shame on me I'm ,among others, a Java web developer, I should know better).
After that, you'll want to meets some gurus and their web friends isn't it ? Ok now meet Dave Shea the creator of the amazingly simple and powerful CSSZenGarden and his Mezzoblue.
Also go see Google's new Visual Design Lead, Douglas Bowman , and his Stopdesign.
Please look at these guys references and what they're visiting (their sites are organized as blogs, it won't be hard to find them) , all are worthy resources.
For a quick start in CSS layouting please go here. For TONS of CSS resources go to CSSVault. Want some Stylish CSS ? : Stylegala. Maniac already ? : CSSMania. Everything Web Development and even more ? : Web Developer's Handbook. I will stop now.
If there are more (and I am sure they are), and you think they're worth looking at, please post them as comments so people reading this can get all the help they need
So, to resume:
- A LIST apart
- CSS Zen Garden
- Sample CSS layouts
- Web Developer's Handbook
p.s. If you'll post others as comments, I pormiss to evaluate adding them to the list, but I reserve the right to list them :-)
update: thanks to all who contributed to the list of resources.