The Mozilla Developer Network is a large, high-quality body of refrence materials, tutorials, and demos related to web development.
The official reference documentation for the p5 javascript drawing library. You should have this page open anytime you are working in p5.
Good Resources for Learning Git and GitHub
A list of helpful sites related to Git.
Pressing Command-Option-J in chrome opens a powerful set of developer tools. You can learn a lot about these tools through experimentation, but if you really want to dig in, these are the official docs.
Javascript & JQuery and HTML & CSS
A pair of books on web development targeted at designers. Recommended by Ben Lang.
Tutorials from the source. Breifly covers a wide range of basic to more advanced topics.
Javascript and P5 at Khan Academy
A complete online intro course to programming with Javascript and P5, presented with code-a-long screencasts. This course covers much of the same material as the first section of this class.
An introduction to javascript presented as a series of micro programming tasks.