I haven't read a lot about this online but I know it's one of the problems with remote work.
Details/legalities are going to vary depending on where your company is registered, where your nominal "offices" are (some/most legal jurisdictions still insist on the fiction of a registered office, even though the whole point is to work completely decentralised) and where you're hiring people. So a book/website/wiki/whatever covering all the legal, tax, compensation, worker rights, healthcare, etc., etc. for all the combinatoric possibilities seems unlikely. A high bar and of limited value, since the rules are in any case shifting all the time. So it ends up roughly where we are, with each company hacking through the specific cases that cross their paths with their respective lawyers and accountants.
In this regard, the one thing I have seen is that most Remote First/Only companies I've tripped across seem to throw the questions of healthcare, home office allowances and even income taxes over to the employees... it's already too complicated for them to deal with unless they severely limit the number of countries they'll hire from.