TLDR: This Responsive Web Design Essentials course focused on HTML and CSS is the perfect coding introduction for new web creators. Back in the old days, serious web coders used to do the ...

How do I learn to code in HTML and CSS on my Mac? Web design is one of the most useful skills you can learn, and it’s easy to learn HTML and CSS (the two main pillars of web pages) in Mac OS X.

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.

Thimble won't teach you HTML directly—you'd still want to have something like Codeacademy on hand—but it's a tool that makes learning a lot easier.