very new to growing

hi all...after several attempts to germinate my seeds i have finally got three seedlings potted and i have plants about 3 inches tall now in 11 ltr pots under a 600watt growlight....in an airing cuboard......can ant give advise on watering and care....and please keep it simple cos im as think and green as they come...18 hours light six hours dark...12/12///...i mean WTF......i really want these plants to do well as i would like to prove the theory to myself.im really getting into this and have tried to read up as much as i can but i seem to have drowned myself in info i dont really get.....any help would be very much appreciated folks.thankyou.M:rasta: