Don't Make Me Think - Originally written in 2000, Don't Make Me Think is one of the original books on web design and usability. Although it's been around for a while, the goals and lessons of the book are universal and apply to websites today.
CS50x - HarvardX (edX) - An introduction to the intellectual enterprises of computer science and the art of programming.
Coursera - "Compilers" by Stanford - The course explores how high-level languages are compiled to low-level assembly.
The Elements of Typographic Style - The primary form of communication on the web is through text which makes typography one of the most important aspects to design for.
Udemy - Online Courses - Learn Anything, On Your Schedule
Rationality: From AI to Zombies - How to make good decisions under uncertainty.