Blender - open source and very powerful (most definitely professional-level!) animation package.

The Foundry incorporating NUKE (Used for Avatar)

Animation Master- Excellent animation software and very cheap!

Learning Character Animation with Jeff Lew

Maya- Industry standard animation

Zimmer Twins - Simple animation-making

iStopMotion - Not free, but the best stop-motion package for Macs.

Framethief - Okay, okay, a FREE frame-grabber (stop-motion package) for Mac...

...And one for PCs - it's not free, but you can trial it!

CartoonBrew Great resourceful animation news.

CGSociety Interested in learning more about the 3D industry and their processes in lighting, modelling, texturing, compositing etc.

Spline Doctors Pixar animators at Day, Animation Podcasters at Night :) Podcast opened by several Pixar animators discussing and providing tips on Animation. Its all about the story and acting :)