Can anybody help a lady figure out where I connect the wires on the audiophile sub harness on a 2002 ford sport trac explorer? Also, I am guessing this is where the 5v 12v regulator should be attached, is that right?

You'll need a resistor between 2.2k and 3k ohms. Then the resistor gets connected placed inline between the avics remote lead (blue/white) and the harnesses remote wire (blue/white).

Thanks for the info! After wiring everything, is it ok to splice everthing that needs to be grounded to the one ground wire of the avic harness, or should I ground each one seperately?

Find a screw or bolt that attaches to the chassis of the car and ground everything that needs to be grounded to it. And it's better to run each ground wire all the way to the grounding point individually rather than splice them all into one wire and run that single wire to a ground.