I have a friend who's a doula and recommended Childbirth International. I'm not sure if you've already chosen a program or not, but after doing the compare and contrast I can see why she went through them over DONA or ALACE.
While those organizations might be fabulous, they nickle and dime you to death (recertification fees, workshop fees, annual membership fees, etc) and don't offer near as much support or flexibility as Childbirth International does.
For instance, through CBI you could start today... that isn't the case with any other doula training program. There are weekly chats, your introductory class is free, you can pay for your training in installments, recertification and annual membership is free and they also offer trainer support to name a few things.
Here's a link to a Comparison of Doula Programs: http://www.childbirthinternational.c...omparisons.htm
I'm planning on starting Doula/Childbirth Educator training in Sept. I've done loads of research on the programs out there and think that this place really is most benefical to me. Even better is that both courses are only costing me $850. Not bad.
Good luck in whatever you decide. Being a doula is a pretty awesome endeavor!