Which are the best lights to use, hps or hid??
answer: hps comes under the hid, hid meaning high intensity discharge and hps is a hid, but hps is the most frequently used lights used by pro growers and other growers, the other options are metal halide, which is also a hid, but this lamp is better used for vegetation growth and not flowering, im not too sure, never used them myself. or easy cheap and simple fluorescents.not thst great but you get by.

How much light does a cannabis plant need in a full day?
Answer:vegetaion growth(just growing normally) 18hours light 6 hours dark
flowering 12hours light 12 hours dark

i have white widow seeds, will it kick out a real stench in the house?
Answer:most probably,widow is a beast of a strain, so im guessing yes!! good luck.

what should the distance be between the light and the plant and at what stage shall I start giving light?
Answer:not too sure. and second part of question--HUH?plants need light to grow, so start giving light when you start growing your plants!