damp/humidity & computers!!

I am about to start an MCSE course & want to set up a small home network. The only place I have avilable is my cellar, which is a little damp. I have a dehumidifier and central heating radiator in there, but was wondering what people think about the possible effects of the damp. The dehumidifier removes about a gallon each day.
Are there any ‘official’ limits?