We have casting directors assigned to each show individually, so the thing not to do (probably) is go directly to the Fox Network.
The best would be to have an agent submit you to a show, to go and audition. That's the standard way and that's the best way. But it's always worth taking a shot and sending your picture and resumé in.
I don't think in all honesty that people would pay that much attention to somebody sending in a snapshot that said, "I want to be an actor." I think that there's respect for the work and the training and we look at it like that.