Fix moisture problems first, then follow our pro tips on methods and materials.
Banish mold—ban standard drywall
It just doesn't belong below grade; mold can grow on the paper coating, and the gypsum core can crumble. Try USG's Sheetrock Brand Mold Tough Gypsum Panels or Georgia-Pacific's nonpaper-faced DensArmor Plus High-Performance Interior Panels. Both got the highest scores on a standard lab test for mold resistance.