He's also the person behind Practical Typography [0], a great reference/guide for essential typography and layout concepts and terms. It has opinionated recommendations covering nearly everything you'll need to make beautiful documents like this one.
Particularly helpful is the practical advice: how to get the desired results in Word, Pages, or with HTML/CSS; not just high-level abstract guidelines. There's everything from keyboard shortcuts for inserting different dashes (to accompany the explanation on when to use each type) [1] to guidance on page margins in print and on the web [2].
0: https://practicaltypography.com/
> The HTML layout at htdp.org is the work of Matthew Butterick, who created these styles for our on-line documentation.
Some of his other work:
https://docs.racket-lang.org/pollen/
https://beautifulracket.com/