The design site CSS-Tricks has their own guide for learning HTML and CSS—but they’ve compiled plenty of alternatives into a wide-ranging but approachable list.

W3Schools offers coding tutorials and reference guides on HTML and CSS. It’s free, but those who pay $95 can earn an HTML or CSS certificate after passing an online exam.

CSS is messy. Why is it so hard? Is there a better way? Rouan Wilsenach answers these questions and gives developers a path forward, treating CSS in a way they understand.

Use this handy, simplified guide to quickly learn HTML and CSS -- a foundation of modern web development.

Could you build an online game using just HTML, CSS and JavaScript? Absolutely! And this book might just help you make that happen. The starting point of Build an HTML5 Game: A Developer’s Guide ...

How to Make a Web Site Part II: Styling and CSS Once you've got basic HTML down, it's time to learn styling and CSS so you can make your HTML look the way you want it. This lesson covers the basics.

If you, like me, prefer to learn about things from a dead tree, I’d also highly recommend Jon Duckett’s HTML and CSS, which is a similarly delightful reference guide to the technology.