This book, Writing the Breakout Novel by Donald Maass, has been out for ten years so you may have heard of it, even if you haven't read it. I highly recommend at least borrowing a copy from the library and reading it.
Maass is a literary agent. What he has done is analyze bestselling books, compare them to the rest, and come up with the differences between what makes a bestselling novel and not. His insights are especially useful if you have a completed novel that you're editing. In fact, many of the exercises in his book assume you have a completed manuscript. There's a workbook that you can also purchase if you decide to follow his advice.
The vast majority of my favorite authors are bestselling authors. When I read through Writing the Breakout Novel, I could pull examples from bestsellers that I had read and see the truth of what he discovered. If part of your goal is to write a bestseller, then I think this book would be valuable to you in your quest.
If after reading the book, you decide that it doesn't work for you or your story, that's okay. At least you're coming from a position of choice and not ignorance.
(I think I'm supposed to put a disclaimer here whenever I recommend a book or product. Any book that I recommend here was either personally purchased by me or borrowed from the library. I don't receive any renumeration from the authors.)