Congratulations on your decision to become a doula! That is something that we definitley need a lot more of, in my opinion! Every woman who wants one should have one for her birth!!!!
I am going through A.L.A.C.E. (Association of Labor Assistants & Childbirth Educators) to get my CBE (Childbirth Education certificate) and I really like them. Their programs are wonderful & very well-rounded & they are very supportive.
I do believe that they are currently re-doing the doula program to make it even better & more well-rounded, so they might not be having any more registration for a few more months, but I'd highly suggest looking into them.
Their website is www.alace.org
May I also suggest that, if you have any interest at all, you start coming to the Homebirth Meetups @ Maternal Wellness Center in Philly? They're a great place to meet other moms & birth professionals in the area. The next one is Monday the ____@____.com website for the center is www.maternalwellness.com (I think!). I actually run the meetings now, so if you have any questions about them, feel free to ask!
Good luck in your decision!!!