Basic wiring information to install car audio amplifiers and subwoofers.
First you will need to hook-up an amplifier. Start this process by running a ground (negative) wire from the amplifier to a clean bare metal spot somewhere in your car. Next run a power wire from your car battery to your amplifier (trunk probably). Be careful and don't hook the wire to the battery until everything is completely done. If the live power wire or battery post touch the body of your car sparks will fly! You will need a deck with RCA outs. Most stock decks do not have this, but you can buy and install an adaptor. Run pair of RCA wires from your deck to your amplifier. Professional installs have the RCA wire on the opposite side of the power wire. If you don't want to spend the extra time it won't make a big difference. You will also need to run a small single wire from the deck to the amplifier. This will be your remote wire, it tells the amplifier when to turn on and off. Now your amplifier is wired.
Next you will need to wire your subwoofer(s) to your amplifier. Almost all subwoofers need to be placed in a air tight box. They will be wired from the voice coils to terminals on the speaker box. Plug your speaker wire into those terminals and into your amplifier. Be sure to always hook positive to positive and negative to negative when wiring subwoofers or any other speakers. Negative wires are often labeled with a line running down them.