Anger, of the Seven, is the most obviously deadly of the deadly sins. Every day on the news we see anger lead to death. But that's not really the kind of anger that is meant on the list of the Seven. A murderer's anger has long since turned into extreme bitterness and then rage. The kind of anger listed in the Seven Deadly Sins is the initial source that has the potential to turn into something far worse.
Anger, by itself, is simply a natural emotion. It would be inappropriate to never get angry (injustice, for instance, should make us angry). Our problem is not that we get angry, but what makes us angry. Far too often seemingly small and somewhat insignificant matters upset us. Winston Churchill once said that "A man is about as big as the things that make him angry." The trick is to get angry over the right things and to dispense of our anger in the right ways.
There are basically two mistakes we can make in regard to anger. We can vent all our anger emotions all the time OR we can't bottle them up until they explode. The Bible says a fool gives full vent to his anger, but a wise man keeps himself under control. The Bible also commands us not to let the sun go down while you are still angry. Thus, anger is natural, but we have to learn to deal with it in supernatural ways (meaning, in Spirit led ways).
I'm an anger survivor. As a teenager I had a horrendously short temper, but I bet nobody in college would have really guessed such a thing. When I surrendered my life to Christ at age 17, He knocked my bad temper out in one blow (much like Jericho). And so anger is less of a problem for me than, say, apathy.
At the risk of suggesting some very simplistic advice, I'd recommend that each time we experience the emotion of anger we pause and ponder what it is we're angry about. I agree with the ancient Chinese proverb which states that if we are patient in one moment of anger, we will escape a hundred days of sorrow.