Basic magnetism is relatively easy as it is really just metal loves metal.

Wait until you get to Geo-magnetism where the ‘simpleintroduction for dummies’ starts with : *The geomagnetic field vector, B, is described by the orthogonal components X (northerly intensity), Y (easterly intensity) and Z (vertical intensity, positive downwards); total intensity F; horizontal intensity H; inclination (or dip) I (the angle between the horizontal plane and the field vector, measured positive downwards) and declination (or magnetic variation) D (the horizontal angle between true north and the field vector, measured positive eastwards). Declination, inclination and total intensity can be computed from the orthogonal components using the equations*

*
*where H is given by

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*The International System of Units (SI) unit of magnetic field intensity, strictly flux density, most commonly used in geomagnetism is the Tesla. At the Earth’s surface the total intensity varies from 22,000 nanotesla (nT) to 67,000 nT. Other units likely to be encountered are the Gauss (1 Gauss = 100,000 nT), the gamma (1 gamma = 1 nT) and the Ørsted.*