To paint wood paneling, wash it, sand it, apply primer, and then use a roller to apply the paint. HGTV recommends using a multi-purpose primer sealer, 220-grit sandpaper and interior latex paint.
Wash the wood panels with water and a little mild detergent to remove any dirt that may deform the paint or cause it to not adhere properly. Next, sand the surface of the paneling.
The sanding technique for wood paneling is called scuffing, and it roughens up the wood so that the paint primer can better adhere to it. Skipping the sanding step can cause the paint to chip and fall off after the paint dries.
Apply the first coat of primer to the paneling. For wood paneling use a water-based primer, or use a shellac-based primer for wood paneling with a veneer. It's best to apply at least two coats of primer before painting.
Once the primer dries, apply the first layer of paint. Bob Vila suggests using a foam sponge roller cover instead of a traditional roller head. The sponge roller cover applies the paint in a smooth layer without the bumps and dips that traditional rollers can cause. Let each layer of paint dry and sand each layer before applying the next layer.