For writers who want to go the traditionally published route, there’s a process. It usually involves pitching to agents, then having your agent pitch your book to publishers.
A lot of people are working on their novels, so you want to make sure that yours stands out. With that in mind, Electric Lit shares 10 novels that agents have already seen. They include having a protagonist who doesn’t want to be the hero, strange but true stories, and picture books for adults (though if it’s a good book and there’s a market for it, I suspect there’s still a chance).
Speaking of picture books, Writer’s Digest has some advice for pitching picture books. Children’s books are on the rise, but it’s a competitive market. It’s important to know market trends (which currently include humor for kids, beautiful biographies, and lyrical books that resonate with parents and kids). You also need a strong idea, that “taps into a universal childhood experience.” And it helps to tell the story through the kid’s point of view and keep in mind that picture books are often read over and over.
Sometimes you can submit your manuscript (book or story) directly to the publisher. If you go this route, be sure to follow all their guidelines! A couple publishers who accept unsolicited manuscripts (meaning you don’t have an agent) include Quirk Books and GigaNotoSaurus.