Before you paint, get a gallon of "Kilz". It's a primer. It will seal the wood surface for you so you don't have to paint again and again and again. Put a coat or two down....just watch out, it puts off wicked vapors. When it's dry you can paint it. They make bathroom paint that is good for super humid areas.
Make sure you post some pics of your creation and for god's sake, work some duct tape in there! :lol: