I know that stapling is usually the way to go but what is the best/preferred adhesive for gluing roofing paper (when used as underlayment) to a plywood subfloor? As roofing paper is asphalt based, would adhesives designed for asphalt tile be correct.

Thanks for any help.

You dont need to adhere it to the subfloor. A couple staples to hold it down or flip it upside down to keep it from rolling back on ya.