A webpage by the Surry County Health and Nutrition Center, that succinctly reviews some ways to reduce one's feelings of anger. The site highlights the difference between when anger is valid and when it becomes destructive. It is the latter type that is the focus of anger management training.
Anger management is seen as a way to improve one's reaction to stressful situations.
The site briefly lists what is involved in anger management training and the effectiveness of participating in a program.