Web Design: Learning to Problem Solve with Mezzoblue's CSS Crib Sheet
Learning to use CSS can make you insane if you don't have a good instructor. And who does? Some of the best advice I've ever gotten about web communication relates to debugging your code: you have to learn to problem solve efficiently. Enter Mezzoblue's CSS Crib Sheet, may it's url never expire.
You will no doubt come across many quirky layout issues when building a site with CSS. You'll end up banging your head against a wall time and again. This is an attempt to make the design process easier, and provide a quick reference to check when you run into trouble.
I also recommend the attendant conversation, which has whole shmear of mostly excellent advice (I don't recommend removing your DOCTYPE permanently, as one contributor recommends. Everything else is golden advice on this page.)