NYIP New York Institute of Photography
They are great!! I know of at least one Canon Explorer of Light that took the course 20+ years ago and he is amazing!
I had just ordered the course when I met him and was wondering if I made the right choice. Once I received my materials and I had his input, I knew I made the right decision! You can do it at your own pace and you get critiqued on your assignments!
Of course, practice practice practice.