ok mate, im just startin aswell just look on the net for all your answers, specially youtube for screen press tutorials,
but basically as far as i know...
green is emulsion which u need so u can burn the image through
the transparent is the transfer paper, it goes in your printer and you print your design onto it
the light depends on what watt u need i wud go with a 500w+ the brighter the better because it wnt take as long to burn, but you have to get the height right depending on what bulb you got and lighting conditions
the paint is just fabric paint search google youll find loads
as for the t-shirts wht the hell u mean? lol
the rest of your Q's i dunno as i aint even done one screen press yet
^^^ i cud be wrong on all of this but its just what ive picked up on slowly in the past week