Here's "How to Draw the Head from Any Angle" (Direct link to YT Video). Proko studied at the Watts Atelier starting when he was in high school, and later was a teacher there. His way of drawing and teaching is like a 21st century version of art instruction legend Andrew Loomis.
Now he is polishing up the next series, which will be on figure drawing (video link). The first episode of the new series will launch tomorrow.
For viewers who like getting their stuff free online, he is committed to continue producing short videos, but he also offers paid content that's longer and more comprehensive. There is already a DVD and download available of his head drawing material. The figure drawing videos will have premium versions available for a fee.
The Proko YouTube Channel
Proko's website (for newsletter signups and products)
Book: "Creative Illustration" by Andrew Loomis