Ampere's Law and the "Closed Right Hand" rule.
Ampere's Law finds the magnetic field's strngth at a poin tin space due to a current in a wire or the flow of charges.
Finding the magnetic field in a point in space.
The Lorentz Force and the "Open Right Hand Rule"

http://youtu.be/PEjfAWKWXa8

How to Find the Force on a Current Carrying Wire
Charged Particle Moving Through a Uniform Magnetic Field
How to Calculate a Net Magnetic Field
Force Felt by on Wire Due to a Current in Another Wire

by Tony Wayne ...(If you are a teacher, please feel free to use these resources in your teaching.)