There are some really useful techniques to help control your temper. That fact that you're seeking help means you're not in denial which is more that can be said for a lot of 'hot heads.'
Observe the Symptoms - The next time something pisses you off, take note of how your body feels and the thoughts going through your head. By understanding and being aware of the changing mood, you're much more likely to do something to quell it.
Count to Ten - Once you begin to feel the physical sensations of your anger, count to 10 in your head, taking deep breaths in between. Use this time to try and calm yourself down and if necessary, leave the room.
Be Your Own Friend - Visualize your rage as someone else. In your mind, talk to that person and show compassion to them. Support them in becoming less angry.