Light distance pot size and watering for the first days

Hello guys, i am new to all this and i have some questions. First of all i am wondering if it's right to put my seed in a big pot instead of a smaller and transfer to a bigger later. Is there any problem with this? If not how deep should i put the seed? Also i don't know which distance should i keep from light to soil's surface for the first days-weeks. I know the rule with hand in top of plant but what about first days-weeks when there are not leaves etc? I use a 400 watt HPS. How often should i water my plant for the first weeks? same rule for dry surface etc? How much water should she takes for this period? Thanks for all of you and for this very usefull site.