More Than Saying Sorry

I've been dealing with issues of forgiveness lately. There are still people that I harbor bitterness towards, and I need to learn to forgive if I am ever to become the woman I want to be. Is it a matter of saying, "I forgive you" ? I know there's no book of rules about forgiveness, but these negative feelings don't just go away. I don't want to be angry whenever I hear about these certain people. I don't want to rejoice at their failures nor do I want to sulk and mope when good things happen to the ones that I think don't deserve it.