There's more than one right-hand rule, but one version of the right-hand rule that tells you the direction of the force experienced by a moving charge in a magnetic field is:

Point the fingers of your right hand in the direction of the velocity. Curl your fingers into the direction of the magnetic field (if and B are perpendicular pointing your palm in the direction of the field will orient your hand properly). Hold your thumb out as if you were hitch-hiking, and your thumb points in the direction of the force experienced by a positive charge.

If the charge is negative your right-hand lies to you. In that case the force is opposite to what your thumb says.