the basics of biomagnetism is this:

first you must determine which is positive and which is negative. the positive pole is the one the south needle on a compass will point to. the north pole is negative so the north needle will point toward negative. stay away from north/south designators. different disciplines will use the terms in reverse of others. geomagnetic north is negative. some circles call negative north because of this. others use the north designator to mean north pointing, which is the opposite - positive.

once you get the poles right:

positive - is stimulating. it will promote bioactivity, be it healing or be it a pathogen. positive would not be good on an infection, for example, or a cancer.

negative - is calming, normalizing. this is the pole one should use for pain, for example.

positive should never be used alone on the body. if you use positive to heal bones then negative magnetism should also be placed somewhere on the body.

negative pole can be used alone.

those are the basics.