Free coding camp. Social code review. A certification that includes doing real projects for non-profits. Even an interview prep at the end. I am looking at it as a quick way to brush up on current front end dev. They have HTML, CSS, JavaScript, React, D3, Node.js, etc, etc, etc.
I have liked my experience with Pluralsight thus far. It is paid, and therefore the quality is a bit above the background I see elsewhere. I was already employed as a developer when I joined Pluralsight, but it helps me fill gaps in new technologies like require.js or phantom.js
I've tutored a number of introductory CS students and have found w3schools.com to be a fantastic source of reference material for students. Years ago there was some controversy with the site because it taught web standards / conventions which deviated (slightly) from the consensus of sites like stackoverflow. Since then they've made a number of corrections and for the most part have really great content.
Here [1] is a good discussion on quora on the topic. You'll notice that the main complain is out-dated information when compared to MDN. I would argue that MDN is a much deeper source of information that can overwhelm beginners when all they need to know is say, what a <p> tag is.
Please please please qualify these kinds of statements when giving information to beginners who can be easily swayed in the wrong direction by well-meaning individuals such as yourself.