I have a stalk single cd player in my 06' Ford F150 reg cab and I was wondering how can I hook up a powered sub-woofer to the stalk radio?

 

You need a line-out converter to splice into your speaker wires at the back of your stereo. Run RCA wires from there to your amp, then speaker wires to your sub.

So, you need:
Line out converter
Amp
Sub
Enclosure
Wiring