Great Resources

This thread will feature many of the great resources I've found over the years. I'll try to keep it limited to sites that offer free stuff, but sometimes marketplaces may have stuff too cool to pass up.

Stock Photography
www.pexels.com/
pxhere.com/

Textures, HDRI's, & Models
polyhaven.com/
www.textures.com/
opengameart.org/
substance3d.adobe.com/community-assets
texturer.com/
texturelib.com/
ambientcg.com/
www.sharetextures.com/
texture.ninja/
texturify.com/

Software (Free)
GIMP - Just about everyone has heard of this. It's not quite Photoshop, but it can get the job done for most.
Blender - The legendary 3d modeling, animating, and rendering program.
Make Human - Ever want to make your own character? This program is the perfect starting place.
Quixel Mixer - Similar to Substance Painter, Quixel Mixer allows you to make materials for your models.
Magica Voxel - A voxel-based modeling program. From what I seen, it looks very cool, seen some great works of art.
Materialize - This program allows you to generate a material from a single photo. Results do vary. But it's worth checking out.
PurRef - This program allows you to organize and display your reference images on top of any window as you're working. This is a great program to use while modeling, making textures, or painting cars.
LeoCAD - This program looks cool. This is for you Lego lovers who want to build your own sets. This is like a CAD program, but for Legos.