Denial
This can take many forms from denying that a divorce is even going to take place to denial of the emotional pain that's involved. If you find yourself saying "No, really, I'm fine," too early in the separation and divorce process, beware. Face the situation as it really is, head on. Only then can you begin to deal with it.
Anger
There may be many different sources of your anger. infidelity, physical or emotional, real or imagined; betrayal that even the "ever after" has come to an end, and with it your secure, dependable future; being left with the full responsibility of child rearing; being kept away from your children and denied visitation; feeling overwhelmed and stupid over so many unfamiliar chores to be done, like bill paying; sudden insecurity over your financial future; rejection; (Leaver) over ongoing pain inflicted during the last part of the marriage; (Left) feelings of confusion and perceived self incompetence.
This only begins to show the reasons for anger at the end of a marriage!
Bargaining
Some try to strike a deal with the soon-to-be-ex, with God, or any other likely candidate.
Depression
Basically this is the feeling of deep and weighty sadness, often with lingering anger. The physical and emotional symptoms of depression are legion. This is the point at which a lot of people seek professional counseling.
Acceptance
This doesn't mean great joy or riotous celebration. It simply means you have come to terms with the divorce. Both the good times and the painful ones belong in the past, and your future as a Newly Single is what matters now.
The Leaver and the Left will both go through the grieving, but they go through the stages at different times. And it's perfectly normal to bounce back and forth from one stage to another and back, sometimes bringing some of the others phases along for the ride.