Granite is slightly porous, and should be sealed with a high quality stone sealer. Sealing a stone surface is not difficult, or expensive. Because there are several types of stone sealer, it would be best to talk to your fabricator or builder to see what product they recommend. The process to seal a stone surface is to, clean the stone with a mild detergent that does not contain ammonia and allow it to dry for several hours. The next step would be to apply the sealer product according to the directions and wipe off the excess as instructed. It is time to reseal your stone when water will not bead up on the surface. When cleaning stone, there are a couple of do's and don’ts. Don’t use any products with ammonia, strong caustics, or solvents such as Windex. Ammonia will remove the sealer, and strong caustic cleaners will do the same.