Power wash the exterior thoroughly to remove dust, dirt and debris. Allow the cedar shakes to dry for several days.
Inspect the cedar shakes, particularly if they've not been painted before. If any of the cedar shakes look stringy or gray, lightly sand the area with a high-grit sand paper. Wipe it clean with a tack cloth.
Prime the cedar shake rambler with an oil-based exterior primer intended for wood, if that's acceptable for your local building codes. Let the primer dry overnight.
Paint the cedar with an exterior oil-based paint suitable for use on wood. Be prepared to paint at least two coats for full coverage.