I think a good start would be to print these out and place them in a communal area - this source was taken from the WHO.
I would also suggest leaving out hand gel with the hand soap next to all sinks. Truth be told my concern is that not many people wash their hands and of those who do- many do not wash it properly and I think it was reported that 80% of all transmittable diseases did so via poor personal sanitation, primarily in keeping hands clean.
Then there is the added advice the WHO provides
- do not spit in public
- leave a space of about 6” between people
- wear masks only if sick or if dealing with individuals who are vulnerable
Airbnb’s advice were to follow the above but from the hosting side, I could not see much else being added. Realistically hosts would keep their spaces clean and throughly disinfect all areas between guests so... I have no idea.