Better World Blog Yes, this is big brain time.
Z-Lib The first online library where you can download books that are actually readable. Shit, have you ever TRIED reading stuff using "online access" from your local library?! Yikes!
MIT OpenCourseWare Obligatory link to MIT's free online classes.
Project Gutenberg Obligatory link to possibly the oldest website for reading historic books online.
JPL Infographics JPL stands for Jet Propulsion Laboratory. It's a division of NASA. Here is a section of the website devoted to astronomy and science infographics.
The Feynman Lectures Free online physics lectures from a famous physicist known as Richard Feynman. Normally the book set is about $140.
Buzzfeed Surprisingly, quite a few of these articles are very useful for learning things like lifehacks. The trick is learning to browse the site by using the recommended articles you see at the bottom of the page after you click on some inane clickbait article.