elobuddha - check you PMs , i've sent you my email address and we can sort out the books.
My interview was all HR. Stage 3 is now a HR interview and a team building excersie which involves playing a game with the other candiates. The game involves an individual task and a whole team task....the interviews watch whilst you following the instructions. They are looking out for team work (obviously) and how you incorporate your individual goals with the team goals and follow changing rules etc. Its quite fun i wouldnt worry about that.
The interview is very long (mine was nearly two hours straight). It is all standard HR stuff. Prepare lots of good situational examples. They are asking you questions based around the skills/competances a good air traffic controller needs...they therefore need you to be able to demostrate situations in your life (work or social) where you have shown particular skills etc. They also want to know about how you have prepared for the role and about your basic motivation and how you would fit into the type of job role.
I think someone posted a list of questions that could be asked, that would be a very useful thing to go over.
Every interview is personal as everyones examples are different. The interviewers do "feed" off of the information you give to them to a certain extent so you may be asked sub questions after the main question has been asked to help clarify what you have said or to give the interviewers more information about that situation. They will also prompt you if you are going off subject or startig to give examples which aren't really answering the question presented.