To tell if you've set the bridge right, play a harmonic - ie touch a string very lightly at the octave marker, and pluck it midway between the octave marker and the bridge, releasing the string as you do it - should sound an octave higher than normal. Compare this note with the octave note played normally. If the harmonic is higher than the octave, move the bridge towards the tailpiece slightly. Repeat until you're spot on.
Ray