Basic's of Amp and Sub Install, please give some insight..

Ok, i have a 95 ford thunderbird, 2 6/8's in front doors and back panels, 2 6/9's behind backseat(top under rear glass) and 1 6inch round behind arm rest. With a JVC head unit powering ALL speakers(total 7 speakers). Yeah i know that sounds bad, thats why i need an amp, and a sub or two. I fade most the sound to the front, and it is real good. But i definetly need an amp and sub/subs.

Basically, how do you connect these pups. Lets say i get an amp tomorrow, can i get a 2 or 4 way, and let the rest of the speakers work off the head unit. And how do you install the sub's. Could i do it?? Do i really have to pay someone lots of money to do it?? I am very good with working on things, so i think i'd be able to handle it-just give me basics if you could, like what has to be connected to what.

The main reason why i want the amp and subs is cause the speakers i have now, i'd like to cut all the bass to them, so the subs handle that(no popping at high volumes). And the amp to handle all speakers, or at least 4.. Please if you have any input, give it. Thanks alot.

Oh, forgot to mention, all my speakers are high end pioneers. Also, what amp/subs combo do yall recomend?? Not that expensive you know, but not cheap sh**.. Everyone around says that sony sucks?? Are they that bad?? Those xplod subs and amps look good, but i have NO knowledge of em..

Ok, just did alot of reading on the net, and it looks like i want just a mono amp/sub combo. Most likely 1 sub, but a big one-like 15inch. I want to connect all the amp wires(ground, power/+, and turn on wire on head unit) plus the rca input on my head unit. Then just run everything to the trunk, and power ONLY the sub, not my speakers. I can live with lowering all the bass on my head unit, and letting ALL bass play through the sub-does this sound right. Sorry guys i don't know to to much but i'm trying. I want to be able to blast my system without the speakers having bass distortion, so would adding the mono amp and sub help me?? Right now, i put the volume up to 22 it sounds fine, but once past that the speakers can't handle the bass-and start farting out. But if i cut ALL the bass to my speakers using the built in eq, i can put it up to 32 volume and the treble sounds great/just no bass(hence i want me sub and amp)..