My favorite YouTube channel is that of Matthias Wandel:

  https://www.youtube.com/user/Matthiaswandel

A software engineer by training, Matthias was one of the first 10 employees at RIM, and after he "retired" a few years ago he began making woodworking videos. His videos are great because of his background (he grew up working on his father's sawmill) and he brings an engineer's approach to woodworking. I've never done any woodworking, but I enjoy his videos because of the way he approaches and solves design problems.

Some of the marble machines he's made are incredible.