Magic Poser Web
posable model
theposearchives
pose reference images
Pixelorama
for making pixel art, in browser and downloadable
Pixilart
program for making pixel art and a social platform for sharing your work
LibreSprite
program for making/animating pixel sprites
Paint.NET
image and photo editing software
Reference Angle
helps you find references of faces at different angles
POSEMANIACS
3D pose references for artists
Figure Drawing for Artists: Making Every Mark Count
guide to figure drawing with a focus on structure and gesture
Wigglypaint
drawing program that lets you make wiggly gifs
Krita
art program for digital illustrations and animation
GIMP
image editor, photo manipulation, art program, graphic design
Blender
engine for making 3D animation, modeling, art, etc