Blender guru - Free and commercial tutorials
Laverna - Laverna is a JavaScript note taking application with Markdown editor and encryption support.
Khan Academy - Khan Academy offers online tools to help students learn about a variety of important school subjects. Tools include videos, practice exercises, and materials for instructors. Read more about Khan Academy.
OneNote - Get the OneNote app for free on your tablet, phone, and computer, so you can capture your ideas and to-do lists in one place wherever you are. Or try OneNote with Office for free.
The Linux Experiment - Making the Linux desktop accessible: no techno lingo, no command line voodoo, no super technical content.
Todo by Appigo - What sets Todo Cloud apart from your run-of-the-mill to-do and task-list apps is that it is straight-up powerful. It's time to get things done.