Wow great advice, but what are preflowers? Oh yeah i paid for female seeds, so both should be fem:D.
I really dont have enough lights to put on them lol. I think i will invest in a HPS system later after they bud a few times.
Preflowers are structures that the plant starts to grow before they mature sexually during 12/12. On a male plant, they will be little balls on the plant. On a female plant, you will see two little "hairs" making a V shape on either side of a branch right where it connects to the stem.
If you don't have enough lights, you could always buy a couple of cheap desk lamps at Target or Wal-Mart and screw in some more CFL bulbs. Or you could get rid of the smallest plant after you've confirmed that you've got at least one female. Or you could just try your luck with too little light; you'll still get some bud, but it won't be as much or as high quality as it would be with sufficient light.
And yes, you're only going to get one harvest off these plants, after that you'll have to start from seed again.