Hi Ashley. I was reading a book this weekend, "Passive Income, Aggressive Retirement: The Secret to Freedom, Flexibility, and Financial Independence (& how to get started!)" by Rachel Richards. One of the passive income streams of income she covers in her book--which I believe she self-published--is publishing a book. I recommend you read her book and then read the book she recommends for getting published, "Published," by Chandler Bolt.
All the best to you!! :)
"God has put a dream inside you. It's yours, and no one else's. It declares your uniqueness. It holds your potential. Only you can birth it. Only you can live it. Not to discover it, take responsibility for it, and act upon it is to negatively affect yourself as well as all those who would benefit from your dream."
John C. Maxwell