The principle is to have 50w per square foot, or 3000 lumens per square foot. You may need to plan your flowering area and the number of plants you want to grow and work from there. Most books reccomend to put plants in a 12" pot, although I use 10" and many of my friends use 8". Look on this page and find the 2 very cool videos on growing. Very cool. Of course, as my predecessor says, opinions are like assholes- we all have one and they all stink. Books conflict about nutes for seedling, but I find most say to use them very diluted. Maybe because the growing mediums these days are designed for drainage and airation. Who knows?

check out those videos.