There are some really cool vids on youtube under betta breeding that are really informative. I don't think you want 2 females in there when the male is ready to copulate, and I remember reading on the internet a while back that its best to set up the tank so its only 1/2 full and to have half a styrofoam cup floating at the top like a dome to help keep the nest together and the air just underneath it warm for the babies.
It take about 2-3 days for them to hatch, and the male is best left in there alone until they can swim horizontally. If it seems that he might have started eating them instead, then you can take him out.
Have lots of baby fish food ready once they start swimming properly!