How can one find out what pole is at the head of the nail and what pole the point is?

That is assuming that you have somehow magnetized the nail. Bring a compass near the nail, and the north-seeking needle will point to the south pole of your magnetized nail.





The reason for this seemingly odd behavior is that the south pole of the Earth's magnetic field is actually near the north pole. Say that again. The Earth's south magnetic pole is in the arctic near the north pole. So when a magnet points north, that end of the needle is the north pole of the compass pointer.