Firstly, Welcome to the forums. I hope you enjoy it here and stick around.
Thinking back to mine, I remember that you were often faced with a subject, eg. Euthanasia, Abortion, etc. and you had to put forward views and how they relate to the chriastian aspects.
You are relatively safe if you know the main teachings you are taught in R.E on christianity.
eg. Thou Shalt not kill.
eg. Love thy neighbour
eg. God creates and god takes away (or something like that)
Anyway, all those teachings can be applied to any of the subjects you get given.
Eg. Thou shalt not kill would be going against abortion.
I think there are a few more but I remembered as long as I knew those, it would be OK.
Thats as much as I can recall.
Good luck with it all.
This may be useful...
http://www.bbc.co.uk/schools/gcsebitesize/re/