Cartoon Network D.O.C is an amazing site for viewing storyboards, model sheets, backgrounds and more from cartoon network shows.
Cartoon Network D.O.C
Iamag.co
Iamag.co is a huge collection of references for walk cycles. The collection contains illustrations, sketches, model sheets and tutorials…
Brendan Body (Birds)
Brendan Body has a great post on his website which displays lots of great reference and observations on birds and flight.
Animators Resource
Animators Resource is a similar website to this one but focuses more on specific posts and videos rather than linking to other websites.
Quickposes
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
Living Lines Library is an amazing resource full of pencil tests, drawings, documentaries and more from the animation legends!
OpenToonz (FREE)
OpenToonz is a free open-source software for producing 2D animation and is known for being used by Studio Ghibli
Animator Island
Animator Island is a treasure trove of animation secrets, techniques, tips, and information on your quest to become a Master Animator
Posemaniacs
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.
Animator's Resource Kit 