Even better then unscrewing the bulb - a screw in adapter with pull chain - so you can turn the light off and on, when the fan is running.

A cart with casters to hold bins of stuff makes it easy to roll your darkroom materials in and out is good, and adds a work surface too.

Here is an example:

http://www.target.com/b/ref=in_br_br...%3A%2425-%2449

Matt