How to prep basement cinder block walls for painting? Moisture & mold.

http://homeguides.sfgate.com/paint-cinderblock-wall-23561.html

a product called Damptite will seal and whiten your walls.

First you need to find the source of the moisture. No matter what you do on the inside, if you don't fix the problem it will continue to come back. If it's grading, re-grade the area outside before starting on the inside. If it's moisture seeping through the walls because of improper sealing, you may need to dig out and use a moisture barrier on the outside before proceeding. Don't try to short-cut a damp basement problem. It'll just be worse on down the road. Using a dehumidifer in basements is always a good idea. Good luck!

Sealer coat of paint.