For safe mold remediation, arm yourself with goggles, gloves and special N-95 or P-100 respirators, especially in extreme cases. Wash the mold off infected areas using a 1-to-8 bleach/water solution. This removes mold from many common household surfaces in a matter of minutes.
It is important to wear older clothing and footwear that can be either laundered or discarded after mold remediation is completed. Moisten moldy spots constantly with water (such as with a garden sprayer) so that uprooted spores don't enter the air, and ventilate the room with open windows and an old/cheap box fan that can also be discarded. Make sure to turn off any air conditioners or furnaces, and cover air ducts so that spores don't spread throughout the house.
Cut out any mold-infested carpeting, wrap it, and tie it with tape so it retains that form. Next, place that carpeting along with any other moldy debris in doubled trash bags for later disposal at a municipally approved site.
Even if all the mold on accessible surfaces is removed, this does not mean that there is not further infestation below. If it has reached the drywall, remove the entirety of the affected portion. To avoid compromising electrical wires, poke holes through the drywall first to locate them, and then kill the power. Pick up any remaining smaller moldy debris with a dry/wet vac.