What are the best resources for learning CSS well?

CSS is kinda crazy compared to programming languages - I mean that where things make sense in programming CSS makes your brain ache when you work with it. The best way to get over that is to work with it to get a feel for the syntax, Once you get a handle on that it gets way easier.

Two books that helped me the most were:

Stylin' with CSS: A Designer's Guide by Charles Wyke-Smith

This is kinda dated but does good on getting the basic structure down with a little bit on how CSS makes pages look better.

Handcrafted CSS by Dan Cederholm with Ethan Marcotte

This goes more into improving styles and how to get things working better and simpler CSS.

Both are showing their age but the approaches work for the programmer brain (more-so than books written for those who don't know programming logic at all.) Once you get these basics down, you will be able to understand what's going on when you look over googled results of what things you want to do. (and see how badly overloaded a lot of commercial sites are)

Still gonna take you months, but hopefully it won't be as frustrating as when I started trying to figure it out.

CSS-tricks.com. Postfix your searches with it and you’ll get well explained answers.