What is the best way to put down hardwood stairs?
Should I nail them on top? as well as use glue and then put wood-putty over the nails so they are hidden?
I would use finish nails, two per stringer, set the nails with a nail set, fill the holes with stained wood putty, of the same color, let cure and then finish if they are not prefinished.
I’m going to assume that the previous poster meant to say to use heavy duty construction adhesive under the steps and then to use the finishing nails to secure. We wouldn’t want those steps to squeak 😉