Different teachers have strengths in different areas. I have learned much from the following teachers:
Yoke Wong (www.pianomother.com). When I first started playing keys in our church’s band, I quickly realized that my ability to read sheet music was of no use because all we had to play from were lead sheets (i.e. lyrics and chord symbols). I needed to learn how to improvise. So, the first course I bought was Yoke’s “Definitive Piano Improvisation” course. I finished about half the lessons before switching to Duane Shinn’s course to focus on learning chords.
Duane Shinn (playpiano.com). Duane has literally hundreds of short but excellent instructional videos on Youtube. He also sells a large number of self-study courses and offers a free introductory course via email. In theory, you’re supposed to receive one emailed lesson approximately once a week. In practice, the occasional email doesn’t arrive. Not only that, but I found it tedious to study the material in an email format. So, I bought his course “39 Lessons on Power Piano Chords”. It’s a single PDF of all the free lesson emails. I worked carefully through every single lesson and established a daily practice routine that includes playing every possible chord (which is what this course explains along with common chord progressions). I also bought “Use Piano Sheet Music Like a Treasure Map” which is good but there are better options to invest a limited training budget.
Zach Evans (www.bestpianoclass.com). I bought his Captivate course (lifetime option). After purchasing that course, I took his massively discounted up-sell offer to get all his courses. The courses have a logical sequence, so I started with the Technique course and am still working through it before I move on to the other courses. His Youtube channel has some instructional videos but mostly covers.