Start by just putting it online. Get a wordpress, or use github pages, or dump a bunch of files in an AWS bucket, but get it online first. Worry about publishing once people start actually asking whether they can get paper or ebook copies, at which point you'll also get people suggesting ways to get it published. The biggest hurdle to having good information accessible to all is folks never putting that information online for the rest of the world to actually learn from =)

Thanks, that’s great advice.

LibreTexts is supposed to be good in terms of authoring and remixing content. They definitely have distribution — used a lot at UC Davis and other big schools, with millions of students reached annually.

If you want to write, publish and deploy - online the tool I am building can help you do that, either via markdown+git or an online editor https://curvenote.com . That would let you write but also use LaTeX math for equation typesetting as well ad numbering, referencing etc... you can also host and deploy it on a free service too as well as convert to PDF/Tex when/if you need to generate a hard copy.

I would start by just publishing articles to a Wordpress site. You'll get long-tail SEO on articles and often helpful feedback. Build up from there and eventually you'll find you've written a textbook.

That's basically what I did with organic chemistry.

Advice about what? Not snarky, genuinely interested. I released v 1.0 of an open undergrad text just yesterday so I have some ideas anyway.