Painting a Driveway

We recently received the following message from Phyllis B. via our website:

My son lives in Delray Beach, Florida and wants to paint his driveway for two reasons: it is a lot less money than paving the entire driveway and it will make the house show much better. Right now, it is gray concrete with some stains from mold. What is the best paint to use and does it need to be primed first? Also, how many coats should be used and should a sealer/sealant also be used? How do you decide on color?
 Any help you can offer would be greatly appreciated.

I responded as follows:

If the driveway is currently bare concrete and has never been painted, I would recommend pressure cleaning the driveway using a bleach-and-water solution and then rinse it with clean water. I would then suggest to acid wash the driveway using muriatic acid, diluted with water (Add water to a watering can 3/4 full, then add muriatic acid to water.) Make sure to wear gloves, goggles, and a respirator. Pour the acid mixture on the driveway and have someone take a large push broom to work the acid into the pores of the concrete. Do this to the entire driveway. If you do not acid wash the driveway, then don't waste your time painting it, because the paint will end up peeling up. You can then pressure clean the driveway again and rinse. Allow the driveway to dry for a minimum of 4 days. To ensure the concrete is dry, tape plastic to a 4-foot section of the driveway to see if moisture gets trapped under the plastic. If moisture is trapped, then continue to allow the driveway to dry. Do this in several areas. The driveway and the ground under the driveway must be dry. Turn off the sprinklers to help the process along, because if the concrete gets wet, the time on the drying starts over.

Once the driveway is completely dry, apply a coat of Xylene-based stain to the driveway, thin out the stain with Xylene (1 quart per gallon) and allow it to dry overnight. Apply a second coat of Xylene stain and have anti-skid added to the second coat of paint so that the driveway will not be slippery. I recommend going to Sherwin Williams to get your Xylene-based stain.

Do not drive on the driveway for at least 7-10 days. You can walk on the driveway the next day. The paint will be dry, but you want it to cure before you drive a car on it with hot tires.