Deja View is a blog by Andreas Deja that showcases a lot of his own work as well as other inspiring animation development posts from the Disney archives
Deja View
Frame by Frame (Blog)
Frame by Frame is a blog that displays sequential images from various animated films for study and appreciation. It also shows the gif to supply reference for timing.
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.
On Animation
On Animation is a website filled with animation analysis, behind the scenes, podcasts and more. Check it out!
Animator's Resource Kit 