Always test your cleaning product or method first on an inconspicuous area to make sure it will not cause damage or discoloration.
Mold is a resilient and potentially hazardous microscopic organism that thrives in indoor environments. It feeds on decaying organic material and although most molds are harmless, several types produce chemicals toxic to humans. Drywall, gypsum wallboard, wood, adhesive, ceiling tiles, paint, plywood, paper and cardboard all contain organic materials that mold can feed on. Cleaning mold can be difficult and unless the underlying cause of the mold is removed (usually a problem of excess moisture) it will return. Since even dead mold can cause toxic reactions in humans, all contaminated porous materials such as drywall and wood will need to be replaced entirely to completely remove mold.
The best way to clean surface mold is to use either a borax solution or white distilled vinegar; both of these products are cheap, safe, and effective. Bleach can be used to clean mold off of non-porous surfaces but it should never be used on porous material; the chlorine in bleach cannot penetrate the surface of such materials but the water which makes up 99% of bleach solutions can, thereby feeding the roots of the mold.
To clean with vinegar simply spray pure white vinegar onto moldy surfaces and let it sit for an hour, then wipe it down with water and dry thoroughly. When using borax, prepare a solution of 1 cup borax to one per gallon of water. Vacuum the surface with a HEPA filtered vacuum cleaner to remove loose spores, then scrub the surface with the borax solution and wipe away any excess moisture or moldy debris. Do not rinse, the borax solution can safely be left on the surface to minimize future mold growth.
The following are common sources of moisture which can lead to mold:
Fixing these problems can be fairly straightforward, install exhaust fans in bathrooms, kitchen, and make sure the clothes dryer is properly ventilated outside. Dry water splashed outside the bathtub or kitchen sink. Have ductwork and plumbing checked and sealed.