Cg Monks Toolbox is a free toolset for Maya that includes a large selection of handy animation and rigging tools
CG Monks Toolbox
Animation Exchange (2017)
Animation Exchange was an 8 hour twitch stream hosted by a bunch of lovely animation veterans. The aim was to take the knowledge sharing and powerful community of art and development conferences and make it accessible to all, and it was awesome!
Tea Time Animation
Tea Time Animation is a website and forum run by Lana Bachynski (Blizzard) that has a bunch of great advice and resources for animators.
Animation Is Hard (Podcast)
Animation Is Hard is an animation podcast hosted by Mike Stamm and Matthew Krick where they walk you through the challenges and pitfalls of producing independent animation, and share their advice on everything from scriptwriting to crowdfunding.
Alejandro Garcia
Alejandro Garcia has a huge Youtube video series all about physics in animation, covering topics like forces, weight shift, jumping and more!
Morgan Loomis Tools
Morgan Loomis has a bunch of great animation tools and scripts for Maya on his website free to download. You can download the full animation shelf or get them individually!
Animsquad
Animsquad is an online animation school that has courses of all levels that include advice from industry veterans, individual masterclasses and high quality rigs.
Gnomon Workshop
Gnomon Workshop has a wide selection of animation courses from performance and acting, creating game ready animations and more!
Animation Buffet
Animation Buffet is a great resource for free Rigs and is constantly updated by Jean-Denis Haas (ILM)
Animator's Resource Kit 