well, i havent started working as cc yet but i can give you advice on the interviews!!
mostly, they all run along the same sort of lines with group activities, an exam (sometimes on the history of the company so revise well!) and then a certain number of people will be called for a 2 on 1 interview.
They are mostly looking for how well you interact with others, your personality and if you can work as a team. all the ones i have been to have been quite relaxed and nothing to worry about!
good luck!