I hate self promotion. To me, there are few things less genuine than hawking your wares through social media. At the same time, I understand it is a necessary evil. You've gone through the trouble of writing something awesome, but now it gathers dust on your mantle while you waste away, drowning your existential sorrows in snifters of the finest brandy.
Or maybe your process is different than mine.
In any case, you'll need to understand how to sell your book to move forward in your career. Since I have some experience there (I've sold book before) I figured I could offer some words of advice.
But, I'm also recovering from what can only be described as a case of the little death. So I'll hand off to one of the finest writers on the subject: Chuck Wendig.