Do you recommend felt or Rosin paper? Or does it depend on the installation? I'm installing 3/4" thick prefinished am. cherry over a plywood subfloor. I already bought rosin paper, but does it really matter? Should I overlap the paper?

Thanks!
-brian-

You should follow the instructions that came with the flooring! But generally speaking, on 3/4" solid, you would use 15lb. asphalt saturated felt lapped over by 4" on the seams. Rosin paper has zero moisture resistance whereas the asphalt felt is considered a vapor retarder.