By Relocation.com
If you have new wood siding, be sure to brush the wood clean from the top down. Caulk after you stain or prime. Set the nails the carpenter missed below the surface and fill the nail holes with caulk weathered wood siding.
Stain bonds to unpainted wood that has weathered.
If you do plan to paint, then sand or power wash the wood to remove any gray weathered surface and to smooth siding that has been exposed to the weather for more than a few weeks.
If you're staining, use a wood restorer or power wash the wood to bring it back to its natural color so the staining produces the desired color.