When the photography bug first bit me I did a lot of research on the best online photography workshops, and read a ton of reviews on photography courses. I knew that I wanted something that let me spend the time when I had it, given that enrolling in an evening course just didn't fit the working-mom schedule.
Finally, I can't personally speak to the course yet, but I have purchased Erin Cobb's Clean Color and have heard outstanding things about it. It comes recommended by Karen Russell and at the conclusion of her workshop a week is spent on the Clean Color workflow. I'm hoping this fall to spend some time learning's Erin's editing flow to improve my post-processing.