1. Be able to time contractions. Download an app for your ipad or iphone to accurately time contractions. I like iBirth or iDoula but anything will work, even a kitchen timer and notepad. Practice before labor begins to get the hang of it. (When I'm called to join a labor, I ask how far apart are the contractions, how long each lasts, and for how long the contractions have been going on for overall.) The iBirth app has videos showing labor positions and suggestions on what to say during labor and many other useful lists.
2. Know the stages of labor and what to expect during each one. The Birth Partner is an excellent guide for anyone supporting labor and birth. It covers the role of each member of the birth team, medical interventions and natural approaches, and what to expect in the event of a necessary c-section.
3. Don't take anything personally. Women communicate with their whole body during labor and swatting a hand away, etc. is common! I once witnessed a dad get his face palmed so the mama could continue making eye contact with me. We all laughed about it later and no feelings were hurt.
4. Keep her relaxed, rested and nourished. Use music, provide water/tea and easily digestible foods, run a bath, give a foot massage, etc. Remind her to rest and that labor will progress on its own; there isn't a need to take long walks to "get things moving". It is a time to conserve energy and try to sleep between contractions.
5. Be supportive and present. Avoid watching TV, using your phone, etc. unless it is regarding labor. Here is a list of things to say and to avoid saying during labor.
6. Get support for the immediate postpartum period. Interview postpartum doulas ahead of time and sign a contract to secure assistance upon arriving home. All help is appreciated when a new baby is in the home but doulas are trained to facilitate the bond between mother and baby, help with breastfeeding and recognize the signs of postpartum depression. I like the video in this article and the printable list of postpartum depression symptoms. Educate yourself and take action before a problem embeds itself.