I recently recorded some audio and didnt use an off board mic (dumb i know). The hum, which comes from the camera itself i think, isnt really that bad, but to me its noticeable. I noticed that FCP has a hum remover. How do I use it? What setting should I put it on etc...

hmmm, each hum is a little different so there isn't one 'right' setting (hence the need for various settings). What I would do is using keyframes, sweep each parameter, listening to where it sounds the best. Then take away the keyframes and leave the setting where it sounded the best.