How to paint cement?

I would pressure wash it first to insure that it is completely clean and free of debris, dirt, etc. Then, let it dry completely before painting.

Pressure washing would be good but after that. Get a paint roller sleeve with long nap. Place some kind of drop cloth close to foundation to keep from picking up dirt with roller. Use porch and deck paint.

Make sure to pick the right paint as well, one that is designated for concrete, here is a link with steps:

http://www.doityourself.com/stry/how-to-paint-your-concrete-patio

hose it off first, use a primer for concrete. Let it dry for two days. Paint with outside, exterior latex when no rain is forecast for 5 days. It may need a second coat to look good. Mine need 2 and is perfect. Roll on the paint with 1/2 nap roller. Cover carefully so you don't miss anything. If you do, wait till it dries and go back and cover that place again. Any loose concrete needs to be removed. It won't show from the street. Let it dry completely before painting after hosing it off. Damp concrete will not let paint cure and harden and make for a lousy job.

You can also use a stain like UNicorn spit!