actually it would be best to keep the SAME weight in each hand. That means you should stop using barbell and switch to arm isolated exercises. When your weaker half gets tired, thats the end of the set. that means your stronger half wont be worked as hard and ultimately will not grow as fast. eventually you will even out.
until you have more experience lifting, I recommend isolation in all your workouts. (i.e single leg leg raises, single arm curls, single arm presses, etc)