Today's fathers want to be far more involved that the father, or at least the stereotype of the father in the past. A father often wants to be present at the birth, to help his partner cope with labor pain, or to help care for the newborn baby both at the hospital and at home. A doula will help a father participate at the level he feels comfortable. Doulas can help a father know what to expect, how best to provide support, help him advocate for his partner in a medical setting he is unfamiliar with, and to know how to cope with stressful events.
The experience for the father is an emotional one, which may make it difficult to be objective. Since he most likely has little actual experience in the subtleties of labor, he can benefit from the doulas specialized labor experience. A doula will help him feel more relaxed, guide him in knowing the best methods for helping, the best times for providing massage or helping change positions, guidance on when, how and what may work best, as well as helping him to understand and expect things such as his partner's labor pain. The doula does not replace the father, but instead allows him the freedom to focus his energies on providing love and support, while the doula can focus on making the experience memorable for both parents.
Here are three good resources for Dads: