Just renewed mine. I can echo Mutt's comments. Everyone is friendly. I suspect you will be examined by Dr Natin, who is very affable and a pilot himself. You may not even need a paper as they are very efficient. I was out in the street again clutching my piece of paper in very short order. Admittedly you will be getting the full treatment this time so perhaps a newspaper might be a good idea. Nurses take you away to check blood pressure, hearing, ECG etc. Then you're handed back to Dr Natin for the final checks.
The only preparation I ever make is to avoid drinking sessions the night before and cutting back on my sugar intake that day. Probably unneccessarily. But no harm.