As you near the birth of your baby, it is helpful to learn about the 3 stages of labor.

The First Stage of Labor
The first stage is the start of labor and lasts until the cervix is fully open at 10 centimeters. This is the longest stage of labor and can last 12 to 17 hours.

This stage is divided into early labor, active labor and transition.
1.         During early labor, the cervix dilates from 0 to 3 centimeters. Contractions may last 30 to 60 seconds and occur every 5 to 20 minutes. There may be a pink, slightly bloody or mucous discharge from your vagina. You may also experience backache, nausea and diarrhea.
2.         During active labor, the cervix dilates to about 7 centimeters. Contractions become stronger and longer, lasting about 1 minute and repeating every 2 to 4 minutes. Pain medicine may be given at this time.
3.         During transition, the cervix dilates to 10 centimeters. Contractions are stronger and occur more often. You may feel intense pressure in your lower back and rectum.
What you can do:
Relax between contractions. Use the breathing or relaxation techniques you learned in childbirth classes or ask your nurse for help. Do not push until you are told to do so.
What your partner can do:
Encourage and comfort. During early labor, help her change positions every 1 to 2 hours. Provide ice chips and lip balm. Use touch and massage. Use encouraging words.
 
The Second Stage of Labor

The second stage begins when the cervix is fully open and lasts until the baby is delivered, about 1 to 2 hours. During this time, staff will tell you when you can push and help support your body as you deliver your baby.

What you can do:
You will be encouraged to push with each contraction. You may be told to push more gently or to stop pushing at times.
What your partner can do:
Support her body during delivery. Encourage her and help her count while pushing.

The Third Stage of Labor
The third stage is the delivery of the afterbirth called the placenta. This is the shortest stage of labor, lasting 15 to 20 minutes.
What you and your partner can do:
Relax and enjoy this time with your baby.

Source: healthyinfotranslations.org