93 Talon- Electrical problems, please help.

[eagle talon guy]

Okay...something is really fucked up wit my car.
First of all, when I turn my key to the on position, there is a weird like rattling sound comming from somewhere, but I can't figure it out.
Then, when the key is turned to the on position, or even the accesories position, I have no lights, and my stereo deck doesnt even turn on. But when I start the car, I have lights and stereo!
Then, when I hit the brake when the car is on, my stereo shuts off! WTF?!

Does anyone know wat any of this could be? I need to figure it out...and soon.

Thanx