My Brake lights won't go off and it drains my battery.. what can I do about it??

There's a switch on the brake pedal arm called a "brake pedal position switch". It's a plunger type switch that the pedal arm depresses when you step on the brakes. Check that it hasn't been bumped and is in constant contact with something keeping the brake lights on. You'll have to get down on the floor to look up along the brake pedal switch to see it.