One of the best online resources on animating /drawing/painting is Aaron Blaise's Creature Art Teacher .com and his YouTube Channel Art of Aaron Blaise.
Aaron is currently animating a short film , Snow Bear . He has been doing a series of livestreams showing his process of animating in TVPaint. This is a great way to learn, by watching a master animator at work. (it's like you get to look over his shoulder to watch him animating).
See:
Aaron Blaise's Making-of Snow Bear livestreams on YouTube
(click that link to see all the Making-Of Snow Bear livestreams)
