- What do you do? Most will say "massage, moral support, talk you through the tough parts, suggest positions," that sort of thing. Make sure it sounds useful to you. Watch out if she simply says "whatever you need me to do" and can't elaborate.
- What do you see as your role in a homebirth? A lot of doulas specialize in being your advocate against the big bad OB in the hospital. Make sure she's comfortable with a non-adversarial role with your MW. Also, ask her if she's worked with your MW before and how it went, and ask your MW about her.
- What's in your package? Any pre-birth or post-birth visits?
- Do you do nursing support? Do you have experience with moms having trouble nursing at first? what do you do in those cases?
- Do you help clean up?
- What is DH's role in labor & birth? My doula told DH what to do and let him do everything, to the point where I got the impression that she did nothing the whole time. Make sure she's willing to support your DH to play as big or small a role as he wants.
Tell her what kind of a birth you want. Be as specific as you can. Give her a good sense of who you are and what you want. Make sure she loves everything you tell her and is completely down with it.