Quickposes is a tool for art students, illustrators or anyone who wants to focus on improving their drawing skills. By practicing gesture drawing you will not only get better at recognizing certain aspects of poses, but you will also build a visual library of characters and models.
Living Lines Library is an amazing resource full of pencil tests, drawings, documentaries and more from the animation legends!
Mixamo Auto-Rigger is a free online tool that allows you to upload any 3D human model with two arms and two legs and get it rigged with a full skeleton and skinning weights.
OpenToonz is a free open-source software for producing 2D animation and is known for being used by Studio Ghibli
Source Filmmaker is a free movie-making tool built and used by Valve to make movies inside the Source game engine. It is a full package and can be used to make cinematics using Valve models and environments.
Animator Island is a treasure trove of animation secrets, techniques, tips, and information on your quest to become a Master Animator
Posemaniacs is good free resource for searching for specific poses at various angles. It has 1000s of poses displayed by male and female 3D models.
Line of Action is a really useful site for learning about the human form, anatomy, speed drawing and more. Useful for both 3D and traditional animators!
Animator's Resource Kit 