Bare oak wood is porous and absorbs paint quickly so you must treat the surface with a base coat of primer or the new finish will ultimately fail. In addition, you may need to condition the surface with sandpaper, depending on its overall state. Also ensure you select the correct type of paint for the location and function of the oak surface.
Wipe down the oak wood with a tack cloth.
Cover with painter's tape those areas on or adjacent to the oak you do not want painted. Cover areas below the oak with fabric dust sheets.
Coat the oak wood with latex primer, using the latex paintbrush. Wait two hours for the primed oak to dry.
Wash the brush with water.
Coat primed interior oak wood panels with satin latex paint. Use a semi-gloss or gloss latex paint on interior oak wood trim. Wait two hours for the finished oak to dry. Add another coat of paint if you can still see the primer showing through.
Use an acrylic latex primer and paint to coat exterior oak wood surfaces.
If you are painting an oak deck, use paint specifically formulated for decks.
If the oak is varnished, you must sand off this glossy layer prior to application.
If the oak trim is stained, use an oil-based primer.
Tack cloths are ideal for removing dust from oak. Don't use plain rags, or you may have problems with adhesion.
Ensure the paintbrush is specifically manufactured for use with water-based coatings.