Where are black holes generally found in a galaxy?
Most or all galaxies appear to have supermassive black holes at their centers and probably have stellar mass black holes scattered throughout.
Supermassive black holes found at the centers of galaxies are related to the properties of those galaxies in the following way?
Not really "a" black hole - many black holes. It is currently believed that all, or most, galaxies have a huge black hole at its center. Any galaxy should also have lots of smaller black holes - so-called "stellar" black holes, because they have approximately the mass of a star (larger stars can become black holes).