Rule of the Thirds

I've been having a bit of trouble lately on placement of the main render/stock/person/w.e thingi. So the rule of the thirds online say that it should be on the intersection lines or something? Could somebody help me? I think this thread will benefit others too. Where exactly should I place it? I use to place it in the middle, but people say that's wrong?

 

http://alpine.brainkiller.be/Resources/Fullsigtut_techniques.png

read this whole thing

 

Thanks a lot!