AnimSelector is a free and super simple Maya script that allows you to quickly setup selection groups that you can later pickup from a GUI or assign to hotkeys.
Fantasy Crocodile Rig is a free Maya rig that has a super appealing design.
Rocket Girl Rig is a free Maya rig from the VMComix animation blog.
Jasmine Rig is a free rig for Maya that has a load of great features!
Sakugabooru is a huge animation archive used by fans and animators alike to upload and view animation clips from anime movies and shows.
SloMo Ref is a free collection of slow motion animal reference videos on Youtube
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!
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.