Well, Finally something i can comment on...
I joined up 3 years ago as an FOA but decided to re-trade to something more suited to my abilities i.e, Misplacing bags and generally making self loading freight's life a nightmare.
The interviews cover all usual things that are required from a job interview:
Leadership abilities,
How you work in a Team, (They'll want examples of both.)
Previous Job experience,
Clubs you've been involved in,
Hobbies. etc
The questions more specific to the Airforce:
What are your finances like (Are you a security risk?, Debt etc),
Your knowledge of the Airforce and what it does/when it was founded,
Family history ("Are your Parents divorced?" etc),
Aspirations("Do you want a career or do just wanna do 9 years?"),
and the Favorite. "Why do you want to join up?"
Both interviews will be at your AFCO, 1st interview is normally with a Cpl and the 2nd interview should be with a Flt Lt (Mine were). Just remember to Dress smart and have plenty of enthusiasm. It's already been mentioned but make sure you keep upto date on the news/headlines.
Hope that helps.
LM