Six resources for learning HTML

W3Schools

W3Schools is a good encyclopedic reference for tutorials on HTML/CSS/Javascript. I don't know if I can recommend their actual courses, though, since I haven't tried any of them beyond the first lesson. The general impression I have is that the course software is buggy and limited,

CSS Tricks

CSS Tricks is a blog that posts short technical articles telling you how to do certain things in CSS and Javascript. I've found it rather useful in building this site.

Code.org

This is a very popular resource for courses on programming in general, and its course on Web Development is very helpful to people who don't know HTML. However, I have found that it lacks in terms of education in web design norms, so learn those elsewhere (or by eye, as I did).

Repl.it

ReplIt not only serves as an example of great web design, it also has an IDE with the very useful feature of making your site a subdomain of repl.co, allowing you to test your HTML very quickly. Repl.it should not be used as hosting, though, because it does not allow you to choose your own subdomain. I would instead recommend Neocities for free hosting.

Neocities

Neocities is the only website creator I know of that actually lets you write your own CSS. It also has some in-depth HTML tutorials to get your website started, and a community that gives it an audience. I even have a site there..

Your Local Bookstore

There are quite a few books on HTML and on other related topics that go much further in depth than my articles, from publishers like O'Reilly. Go to your local bookstore to find them.