How do you sand and prime furniture made of wood?

If the furniture is painted then you would need approx a 60-80 grit sandpaper, then gradually move to a finer paper. When paint is almost gone finish with about a 320 or 400 grit paper so it is completely smooth. If you want to repaint then you don't need to remove all the paint unless you are painting over an enamel paint with a latex. (oil based vs. water based). You can however prime it with a good primer once the wood is smoothed. Or if you remove all paint you can then stain it. before you paint/stain your wood be sure and remove all dust from the wood with a clean damp cloth. let wood dry and then proceed. good luck and wear a dust mask :-)