Last year I had a talk with a colorist by the name of Alex Jordan. The way I found out about him was from a short YouTube piece he put together on color correction in Resolve. What amazed me by that video was that he was able to explain a rather complex topic in just a couple of minutes. He's a natural when it comes to teaching.
So I went to his website, FilmSimplified.com, where he has a series of color grading and editing courses as well as several LUT packs. I took one of the free courses on getting started with DaVinci Resolve and was pleased to find that the entire course was very useful and very concise, just like the episode on YouTube.
So we had this discussion and I've looked to him as a friend and mentor in the world of color since then. His approach is very practical and the things he discusses always useful.
So if you'd like to learn more about color grading, I'd encourage you to have a look at FilmSimplified.com. Try one of his free courses and see if you learn something useful. He won't waste your time.
Also, if you're interested in buying any of his courses, he's having a black Friday special pricing event where he's offering his full DaVinci Resolve color grading course as well as courses on editing in Resolve, a "practice" course where he actually shows you how to correct and grade several clips, and a lighting course all for $99 USD. That's a good investment.
He also kindly offered to provide LearnLightAndSound a portion of the proceeds of that special pricing so that we can continue to post useful tutorials (full disclosure). You won't spend any more using these links than if you just went to his site on your own.
Even if you don't have the budget for the black Friday bundle, definitely check out his free introductory course on DaVinci Resolve 12.5.