3D Total is probably the most comprehensive online resource for 3D artists, with tutorials, a dedicated community, forums, and a collection of CG artwork available for inspiration. 3D Total also publishes its own magazines and books.
Mike Hermes specializes primarily in rendering. His tutorials will teach you how to make renders look more professional.
Modeling tutorials for Maya and Mudbox, primarily focusing on the human form and UV mapping.
Lester Banks compiles tutorials relating to 3D, Animation, VFX, Design, and Typography.
Nicholas Hilligoss offers some really good tips for making stop-motion armatures on a budget. Many of his shorts are tributes to Ray Harryhausen’s style of stop-motion animation.