Press F1 on your keyboard and search in the tutorials for UV mapping.
In order to place any kind of texture on a polygon object you first have to map the UV's so they are layed out flat into the 0 - 1 space of the UV Texture Editor.This also includes Fur or Hair if you have it although you might get away with automatic mapping for the latter two if you do not plan on doing anything too complicated but best to manually map it.