The easiest and best way to learn .... is to ............ START!
Just jump in the driver's seat and get at it!!
That's what I did when I started PPing, less than a year ago ... just got at it!!!
Like you, I'd read a lot, and even had a few tastes of it at quilting classes, and nothing clicked. Honestly, a year ago I would have told you it was a useless technique and no I'd never do it. Then along came, something that I wanted to do ... and now, I really enjoy PPing. I see it as Dot-to-Dot meets Paint-by-Numbers!
I started with QuiltersCache.com and used their tutorial and basic blocks. Then went on from there.
As with other quilting techniques ... remember there is no one way or the highway method of doing PPing.
You'll discover that there are many different suggestions that will be made ... all can be right, but may not be right for you!
As you go, you'll develop your own style, but if you don't START, that'll nevber happen!!
Have FUN!