Each imprint releases different genres and types of books. For example, Thomas & Mercer is for mystery, thriller and suspense, while Grand Harbor Press is for personal growth, self-help and inspirational works and Two Lions is for kids’ books. When you click on each, you’re taken to that imprint’s books on Amazon. There aren’t any posted submission guidelines, probably because their site says Amazon Publishing doesn’t accept unsolicited submissions at this time. So, as with many other traditional publishers, you’ll need an agent.
Then you’ll need to set up a KW account to upload your manuscript. You’re responsible for designing (and paying for your own cover), making sure to leave room for both the KW log and the individual world’s logo. They offer some free images to help you create one, but as with any self-published book, if you’re not a capable of creating a competitive cover, I’d suggest hiring a designer. Amazon sets the price and offers 35% of net revenue as a standard royalty rate paid monthly for ebook projects over 10,000 words. You can now write shorter stories, too. And there are royalties offered for hardcover, paperback and audio should you be interested in those formats.
I’m in the progress of testing the KW waters…and will keep you posted. I’ve heard that novellas do better than full-length novels, so that’s what I’m writing.