video.cleverthings.com - Bob Ross - The Joy of Painting series taught millions of artists how to paint a landscape in under 30 minutes.
NOTE: Please join us in boycotting the Bob Ross, Inc. company and products! Bob was such a wonderful human being, and the...
https://www.gimp.org/ - GNU Image Manipulation Program or "GIMP" is an open source cross-platform that is my favorite for doing 2D graphics, especially manipulating images and post-processing.
builder.blender.org - Development Versions of Blender 3D - These versions have the latest features, but may be unstable. You can help test them and report any bugs.
NOTE: You should be careful about using development versions in production projects.
https://cgcookie.com/ - CG Cookie teaches how to use Blender 3d, Unity, and sculpting. I recommend starting with their 2d basic art concept courses. They have the individual courses available, but they've organized the course into "learning flows" that track...
https://krita.org - Krita is a free and open source digital painting software. Perfect for concept art, texture painting, creating illustrations or comics. I love how well it integrates with my graphics tablet and pen. Very powerful and full-featured.
https://www.blender.org - Blender is a free and open source 3d animation software. It is incredibly powerful, and a full featured to support your entire 2D or 3D animation workflow.