A while back I enrolled on a "learn Blender" course through Udemy. I think there was a voucher to get the course for about £15 instead of the list price of nearly two hundred. It was actually a really useful course (and got me well on the road to using Blender from absolutely zero).
On a recent trip to Berlin, I discovered the Udemy app and downloaded a couple of other courses; the flights (there and back again) went by in a wink, and by the end of the trip, I was a Blender expert! (ok, that last bit's not quite true, but I did at least understand what a UV map was).
The "Learn Hand Painted Texturing" course was written by a guy using Maya and Photoshop. But the same lessons could easily be followed along using Blender and Paint Shop Pro.
And this particular course was a great purchase at just a tenner.
While I've not quite mastered painting to the same quality as the tutor, Udemy has meant I've gone from complete noob to being able to produce half-decent looking models in a very short time! There's still a fair way to go - but a combined total of about thirty quid for three or four tutorials (the first one was first on offer for about eight quid) has been the best buy of the year so far, hands down.