Dave over at Mezzoblue is compiling a “CSS Crib Sheet.” He originally called it “CSS Best Practices” but using a word like “Best” in your title can be dangerous, as he found out. A lot of the suggestions he got for inclusion were things like “Favor Relative positioning over Absolute” which is more of an opinion.
His list is a “general rule of thumb” that typically separates those that do web sites with CSS regularly from those that are just starting out and are getting overwhelmed and confused by it all. We’ve all been there. It’s worth a read. If you start out here, then you’re already in a position to avoid many of the pitfalls of CSS and get to the reward (and there are a *ton* of those) much, much faster.