LOL stevo. Perhaps you need something a little more basic than the wikipedia link.
Please let me explain.
The heat flux from within the Earth is rather low when we average it out. However the Earth doesn't work like that. Rocks at the surface insulate and tend to slow down the heat. In addition, much of the heat coming from the Earth is concentrated in particular hot spots. Combine a hotspot with a line of weakness in the Earth's crust and we can end up with something quite spectacular.
It's called a volcano. You were going on about them in your post. They look spectacular but the heat they release must be averaged out over the entire surface of the Earth. When we do that, we get tiny numbers. The wikipedia article explains.
