Put on a mask, hit it with clorox and water. Let it dry. Go back and hit it with Vinegar and water, let it dry. Vinegar neutralizes the bleach.
get a dehumidifier.
I have to periodically treat my basement here in Philly if I don't keep an eye on the dehumidifier.
When I bought my house in Lusby, the upstairs bath, and roof around the waste vent were leaking. LOTS of mold inside the walls when I tore out the bathroom. Just treat it, and be done with it.
WHole house mold issues are a different story. But mold in the basement, and other areas where the source can be treated, or at least monitored, I wouldn't be overly bothered with.
Cleaning up a black mold problem
and
Black Mold Education & Elimination - Black Mold Articles - Stachybotrys, Penicillium and Aspergillus. Toxic Black Mold Identification. Toxic Black Mold Removal Articles. Black Mold Test Kits. <------ that one helped me alot when I started my remodeling projects. These guys are fantastic. They have an active forum with LOTS of real Pro's to help and are also helpful on the phone. If you aren't comfortable cleaning it yourself, these guys sell test kits.