Whilst researching a specific LaTeX question, The Bing showed me a website, last revised in 2013, that step-by-step shows someone how to create, produce and manage a self-published ebook.
See the site.
Of particular interest: The site assumes you'll be creating your book in plain-text chapters using Markdown, and that you'll use Pandoc to knit everything together for the EPUB.
Which, incidentally, is the new editorial flow for Caffeinated Press,despite all the luddite Markdown haturz out there. #FeelingVindicated