Tangoman, sound advice here
Be yourself, stay switched on, get your mental arithmetic sorted, remember it comes in 2 distinct parts. Don't be downhearted when people start leaving after pt1 who u thought were ok, stay positive - stick to your guns if you know you're in the right during your individual planning then they want to see that strength of character come through, but balance it up without being arrogant.
It is actually enjoyable !
Good luck - let us know how it went.
p.s check
http://www.timc.clara.net/raf.htm