FYI, I've done this myself several times, though usually working with an extant book, either from a text or OCR dump, or hand-typing it myself (don't ask).
For works which consist principally of standard sections (e.g., Book / Part / Chapter / Section / Subsection / ...), fairly standard font styles (normal/roman, italic, bold, code blocks / pre / poetry), footnotes/endnotes, and perhaps a few tables, illustrations or images, Pandoc-flavour Markdown is far more than sufficient. Writing or formatting is virtually seamless.
If you're writing something with more complex internal formatting, then I'd lean more strongly into LaTeX. You can do most of your initial authoring in Markdown and generate LaTeX from that, for further finishing work, or simply start with LaTeX. The key discriminator here would be either mathematical formulae or complex image placement. Note that creating the output you want in HTML or ePub (itself effectively a specialised HTML format) might still be challenging.
The next step up would be a specific layout tool (Krita or Adobe Illustrator, say).
But start with Markdown + Pandoc and see if you like the results. It should be Good Enough, and if not offers a smooth path to more powerful tools.
For works which consist principally of standard sections (e.g., Book / Part / Chapter / Section / Subsection / ...), fairly standard font styles (normal/roman, italic, bold, code blocks / pre / poetry), footnotes/endnotes, and perhaps a few tables, illustrations or images, Pandoc-flavour Markdown is far more than sufficient. Writing or formatting is virtually seamless.
If you're writing something with more complex internal formatting, then I'd lean more strongly into LaTeX. You can do most of your initial authoring in Markdown and generate LaTeX from that, for further finishing work, or simply start with LaTeX. The key discriminator here would be either mathematical formulae or complex image placement. Note that creating the output you want in HTML or ePub (itself effectively a specialised HTML format) might still be challenging.
The next step up would be a specific layout tool (Krita or Adobe Illustrator, say).
But start with Markdown + Pandoc and see if you like the results. It should be Good Enough, and if not offers a smooth path to more powerful tools.