Most job hunters prepare for interviews by printing off a list of 20 common interview questions, outlining answers, and calling it a day. This is just a start to your preparation, and here's a way to take your readiness to the next level.
Put yourself in the interviewer's shoes. When she's looking at your resume, what questions will she likely develop? Come up with specific experiences that go with each question and work out the best answer when you practice aloud. Then, ask a friend to play interviewer and think of her own questions. She'll likely come up with some that you missed, and you'll feel even more confident going to the interview.
You don't want to sound rehearsed when you're in the actual interview, but I've found that this preparation method doesn't have the effect of practiced delivery. The interviewer's questions will probably be variations of what you practiced, so focus on each question and then think about which of the experiences you reviewed would be appropriate to mention.