When I went to mine, I had rehearsed a lot of different answers to questions that I thought would be asked, but to be honest with you, those questions didn't arise, it was simply the questions that I'd already answered on my initial claim for DLA that I had to reiterate on, the actual Tribunal was held in a big room with table and 4 chairs either side, I had the Judge, a doctor and a lay man, also a representative from the DWP, but I can say that it wasn't so scary as I had imagined it would be, take a couple of friends with you, they can sit either side of you for moral support (that's what I did). Good luck, just be honest, it'll be fine