OK...
First installation, to a ceiling elec box...
The green wire is your ground, it should be connected to the green or plain copper wire in the box. If there isn't a green or plain copper wire present, then there should be a screw to mount the wire to. You should take a close look to see if there's a wire going to that screw from inside the ceiling. This is essential to ensure that the unit is properly grounded. If it isn't and it should ground out for any reason, the potential to start a fire or cause a fatal shock is extremely high.
That black wire should be connect to the black wire present in the ceiling box, and the yellow, to the white.
Installation two, to a male power cord end.
First you need a male cord end, with a ground. Clip the terminate of the green wire, strip the jacket off. The green wire should be attached to the ground prong, the black to the thick blade and the yellow to the thin blade.
Now, listen carefully Johnny. I am not an electrician, by any stretch of the imagination. As I said in my PM, I have run everything from 12v control circuitry to 600V.
I understand your financial situation, but if I may make a serious suggestion. Go to your local Home Depot, Rona or whatever passes for a serious home improvement store, and ask the guys in the electrical dept.
If I was at your place and could see what you had going on in the walls and the ballast itself, I could be more help.
What I've given you here is what I think is the best application, but I will not certify it's the best idea in any way shape or form.
Earth as One is an electrician, you may think of PM him, he's quite pleasant and helpful. I have no doubts he would be a much better help then most of us, lol.