Recs.
Updated
A comprehensive online video course in D3.js, aimed at students who already have some experience with web development.
In the first phase of the course, you are introduced to the fundamentals of D3 - SVGs, data joins, scales/axes, making dynamic and interactive visualizations.
After that, the course walks through 12 of the most useful visualizations that you might want to learn with D3, showing you how to appropriate other people's code that you can find online.
Finally, in the last section, the course shows you how to structure your code in an OOP format, using a proper file structure to manage a more complex web app.
You'll work through 4 exciting projects as you progress, which each get more complex as your skill level and comfort with D3 increases.