Please help me with electric fencing

[GL14Eek]

I realise this question exposes my complete lack of scientific knowledge.

I have an energiser and an electric fence but I can't get it to produce a current. It is blatantly because I am not connecting the wires up in the correct way.

I have an earth rod which looks like it's made of plastic. Do I put this into the ground and connect the "earth" wire from the energiser to it? I have more than one earth rods - why do I have more than one?