Craft is a site that gathers high-quality material from films, graphic novels and other visual media and lets you explore how other professionals crafted it. Giving you access to source files from animators and artists. Free Trial is available.
#Animbreak Challenge is a competition created by Jason Shum where you can win cool prizes for animating things, what’s not to like! You can join on Facebook or Polycount
Live2D has a bunch of software that allows 2D artists to create animations from their artwork. Available in both FREE and PRO versions.
Endless Reference is a Youtube channel that focuses on animation reference. Lots of great human locomotion videos from different angles
Tri Vital has created a collection of awesome Maya rigs and put them on gumroad for free!
The Industry Job Spreadsheet was compiled by Chris Mayne and is an amazing resource for job seekers. It is full of industry job posting and can be filtered to show only animation roles.
Bodies in Motion is an ongoing photographic project that aims to document the power, beauty and possibility of the human body in motion. It is freely accessible to all visitors at preview resolution or you can subscribe for higher quality images.
MakeHuman is a free open-source software that allows you to create and pose 3D human characters. Useful for pose reference.
Animator's Resource Kit 