This will depend on whether there is water getting behind the walls and getting through as moisture and/or in carrying white salts (efflorescence) to the surface. If water is getting behind the walls from ground water, rain, etc., first try to direct rain away from the base of the building by building up soil to the wall to aid run-off, and be sure gutters and down spouts are clean and in good repair, and that down spouts carry rain water well away from the walls.
In any case, if there is water, apply a basement waterproofing coating to the walls. Solvent based, cement-containing products are effective, but ample cross ventilation must be used during and right after application; and wear eye protection and an appropriate respirator. Follow directions as to method of application, and spread rate (sq. ft./gal.). After the water-proofing product has cured for at least a month, apply an all-purpose latex stain-blocking primer, followed by your finish coat. There are water-based water-proofing coatings now available too... follow manufacturer's directions closely. If the wall are free of intruding water, apply an all-purpose latex stain-blocking primer directly to the walls after cleaning them.