Basically you have to choose yourself a person, whether it be an actor, musician, sports person or just a general celebrity of some type (dead or alive) then say something about them, so that the next person has to guess who it is.

For example, if I said "I am the frontman of one of the world biggest Rock bands, we've had a 20 year career and sold almost 100 million albums. Who am I", the next person would have to guess who Iit was. In this case it's obviously Jon Bon Jovi, so then the person to guess correctly goes next.

Here's an easy one to start off with:

I am a singer/songwriter, last year I signed an £80 million record deal and I used to be part of a boy band. Who am I?"