I just took out my subwoofer from the trunk the other day because it was getting cold.
And i just didnt want it to sit around.
I wanna know how to hook it up to a home theater system.
I already have av reciever but i want to hook up a amp to it.
So how would i do that?
Do i need a power supply.
Help greatly appreciated.

The main thing when you get the sub is where and how you place it. For Bazooka's, point it to a corner and play around with the distance in the corner. You might be surprised with the difference.
If you have a normal sub-place it facing the back of the car. After this find a way to secure it in place (using belts or some high friction clot ( any wool cloth ). Remember the base travels through the boot to the car and then to you. So it's how well you tune it with respect to the car.
Use the sub woofer filter if you have on. For high power subs, around 85Hz is good.

^^ what that didnt answer any of his questions. did you even read his question? as for hooking it up at home you will need to know the impedance of the sub in question. is it dual voice coil? car subs usually have a different inpedance than house speakers. if you simply hook it up to your receiver you could burn out the channel you hook it to.