It is time to seal the granite. First clean your countertop thoroughly using a neutral cleaner. Never clean with any product containing acid, lemon, or bleach. Acids, even a light solution of vinegar and water, will eventually etch and damage natural stone. Do not use scouring powders or creams; these products contain abrasives that may scratch the surface. Now apply the stone sealer. Stone sealers will need to be reapplied as soon as you notice water no longer stands (beads up) on the surface.
TIP: While dish soap will not hurt your granite, repeated and excessive use of soap will cause build-up and dull the shine. Also, don't use bathroom, tub and tile, or window and mirror cleaners. The powders and even the "soft" creams contain abrasives that will scratch and dull surfaces. Use only cleaners made specifically for granite and stone.