Go to walmart and get a SOSCHE 1000w amp kit. Run a power wire from your battery to your amp, ground the amp to a place on the frame (sand the spot down to bare metal first). Run the RCA from the head unit to the amp. (Try and route it on the passenger's side or right down the middle, driver's side gets a lot of noise with the cheapie SOSCHE RCA's). Run a remote wire from your head unit to the amp (solid blue wire coming out of the back of the unit). Then set your gain, by ear is probably easiest.
2000 Mazda B3000 TL Edition 2wd
-Gibson Exhaust- -Gangsta' Tint- -31" A/T's- -2 15" SI Mags- -Sundown SAZ-1500D- -LSD- -Torsion Bars Maxed-
*Eventually: Head Lights, More Tint, 5.0 swap, Murdered, Tube Bumpers, Off Road Lights, Body Lift, Better Stereo, More...