A magnetic field is the region around a magnet where a magnetic force may be detected what sort of material do you need to use the force?

Um... I'm not sure what you mean by 'use the force'...

Permanent magnets can be used in dynamos (to make electricity). You might want to look for more about this on the net.

In this device, a conducting coil of wire is inserted between two poles of a magnet (different poles) and the coil is made to rotate quickly. The magnetic field then creates an electric current in the coil which can be used.

This is how electricity is made in most power plants (thermal and hydroelectric power plants are two examples)