I can advise you what not to do. A few years ago having taking redundancy, I was looking for another perm job. I got an interview for this (admin) role at (is it) Chelsea Hospital(?). I really didn't prepare well enough, in that although I had loads of the required experience,I didn't research anything about the hospital. The two ladies who interviewed me weren't impressed, and needless to say I didn't get the job. Good luck with the interview.