www.dona.org
This site explains doulas and their role very clearly, I think. Doulas care for the needs of a birthing family from the late prenatal course through labor to immediate post partum care. They are versed in NON-medical labor interventions to help the birthing mother cope with pain/discomfort during labor and also assist with establishing breastfeeding after birth. The site really is a great resource for information regarding doulas and how to study to become one, if that becomes your goal.
And yes, NPs do work in OB/GYN offices/settings. Many see woman during their prenatal course as well as do well-woman checkups, pap smears, breast exams and post partum checkups.
Nursing News