First, be aware that not all natural stone countertops need sealing. This is only for stones that need sealing. If your stone does not need sealing, do NOT seal! Sealing stones that do not need it can cause problems later with haze, streaking, ghost etching, etc. If applied inappropriately, the sealer will have to be manually removed to return the stone to it's original look. Stones with an absorption rate

From our own StoneGirl (Jun 4, 2009)

Whatever sealer you use, read and follow the instructions carefully and be sure to buff off all excess sealer. For maximum effectiveness, each application of sealer needs to fully cure before the next application - normally about 24 hours.

Here is a how-to for sealing:

You will need the following:

• Home improvement strength alcohol

Lint-free rags or unprinted paper towels (the "Rags in a Box" disposable paper rags found at home improvement stores are really great for this)
Paint pad (those hard, fluffy coated pads they use to apply paint)
Sealer

What to do:

1. Clean your counter tops by wiping them down to remove any food residue.

Wipe the counters with a rag soaked in alcohol. (Be sure to follow the safety instructions on the container)
Once the counters are clean and dry, apply the sealer with the paint pad. You can pour a little puddle and spread it with the paint pad. Work in smaller, manageable areas.
Leave the sealer for the recommended time and buff off the residue with the lint-free rags. Be sure to TOTALLY remove all excess sealer or you might end up with streakiness and smudginess. Change rags often to prevent smearing excess sealer.
Repeat steps 3 & 4 until all your surfaces are sealed.
Leave sealer to cure for 24 hours and test for water absorption. Drip water on the stone to see if the stone still darkens. If it does, another application of sealer is in order.
Repeat the entire procedure until water beads up and no longer darkens the stone.

Do not think that more is better. Work with smaller quantities of sealer and properly clean up after each application. Your results will be better than trying a single, heavy handed application.

For daily cleaning, just use a couple microfiber towels (one dry and one slightly damp) Clean counters with the damp one - you could add some soap to it if you wished - and buff dry with the dry rag. No fuss, and pretty easy