Here's information on competency based interview questions, what you will be asked, tips for answering, plus sample interview questions to review: http://jobsearch.about.com/od/interviewquestionsanswers/a/competency-based-interview-questions.htm
This site gives a great acronym to assist those who may have trouble with the second interview or the behavioral part of an interview. I believe this can be beneficial even to those who excel and/or are experienced at answering these type of questions.(4116)
Career Advice: Competency based Interview Advice. If you've got an interview coming up, you will no doubt face competency based questions. This article will tell you what you need to know and help you to prepare.