Might have it all professionaly installed, but incase I dont...
the sub has two sets of inputs on it..why? And how do i hook that up?

Dual voice coil. how many ohm is each coil?? They make them to add flexibility for how you wire them up. You should always use both coils, that is why you need to find out the ohm rating for each coil. depending on how you wire the coils, series or parallel, you could overload your amp if it is not stable down to the ohm load. look at your amp, is it stable down to 1/2, 1, or 2 ohm? Dual four ohm coils run in parallel will make a 2 ohm load, in series will make an 8 ohm load. If your amp is not stable down to 2 ohm and you run a 2 ohm load to it, it will burn up.

we need to know what amp you are using to be able to tell you how to hook it up.

The amp im looking at has settings for both 2 and 4 ohm.

How many channels does the amp have?

Also, you want to look for a built in crossover on the amp so that you can eliminate the mids and highs going to the sub. It will make it sound much better. If you dont have one built in, you can add them.

go for a class d mono subwoofer amp.