Empty your oak kitchen cabinets. Place masking tape on the wall area surrounding the cabinets to avoid getting latex paint on the wall during your painting project. Lay plastic sheeting on the floor to catch any drips of latex paint as well. Remove your kitchen cabinet doors and drawers, and position them on a flat surface, such as a plywood board placed on top of sawhorses, to paint these objects more easily.
Pour one-fourth cup of trisodium phosphate into a gallon of warm water, and soak a cleaning rag in this solution. Wipe down your oak kitchen cabinets with this rag to remove grease and other debris from the surface, thus enabling your primer and paint to adhere to the cabinets. Sand down any imperfections in the oak cabinets using a light sanding sponge or a light sandpaper, as this helps the primer and paint attach to the oak surface easily.
Apply to your kitchen cabinets a paste wood filler, which is available at your local paint shop. Rub the filler against the grain in your oak cabinets, and then rub the filler with the grains with a cloth.
Put a primer on your oak kitchen cabinets to help the paint stick to the cabinets. Choose an interior oil-based primer known as brushing putty; this type of primer further fills the oak wood grains as it primes the wood. Apply the primer using a nylon-polyester brush, and be prepared to discard this brush after applying one primer coat.
Rub a light sandpaper or light sanding sponge over the oak cabinet primer to flatten the surface. Paint the cabinets as well as the doors and drawers with a latex paint. Allow the paint to dry completely before putting your kitchen doors and drawers back in place.