Nick Agar has recently done a series of eight you tubes on sharpening turning tools. I have found them to have solid technique, good organization, and be "right sized" (long enough to contain plenty of information without being overly long). I have long considered the woodturning DVD which Jeff Farris made for Tormek essential training for Tormek turners. Most Tormek related videos I watch only once. Those which I consider Top Shelf, I like to watch multiple times to absorb the subtle points. I consider these you tubes by Nick Agar Top Shelf.
They are part of the Tormek Sharpening Solutions you tube channel. Here is a link:
https://www.youtube.com/playlist?list=PLGpQjduHna4CJJXg2kiw62y-eRf5WTnyg
Ken