Hi and welcome!
There have been many discussions on this topic. Do a tag search for "children" or "children and poly" and a lot will come up. There is a huge Master Thread about having children and raising them in a poly household. You can also do an advanced search for the words "children," "pregnant," or "kids." I am sure you will find a great deal of helpful stuff (I can't offer more than that, since I'm childfree).
Last edited by nycindie; 11-29-2012 at 04:19 AM.