I have pioneer 6X9's in the back, 6" in the front, and a pioneer head deck. Recently got a Pioneer sub, and sony amp and wiring kit. And only have a slight idea on going how to install them, any help would be appreciated. thanks.

well, where to start?
first you will want to run you rca cables down the opposite side to you power cable, which will be fed through the grommet in the fire wall.
then when your rca's, power and triggers are run, work out where you want the sub and amp mounted, and hook up evrything. Dont forget your earth strap. thats important.
once you have got everything working, its time to tune it. being a 12", i would start with gain at half, and the freq at around 80hz on the low pass filter. then turn up your gain till its good, and mabey you might have to lower the freq to around 60hz. then you should be good.

well, where to start?
first you will want to run you rca cables down the opposite side to you power cable, which will be fed through the grommet in the fire wall.
then when your rca's, power and triggers are run, work out where you want the sub and amp mounted, and hook up evrything. Dont forget your earth strap. thats important.

thanks man, ill get on to it asap, but probly get sumone thats done it before to help me, lol.