Make sure your brakes are adjusted properly since the strength difference between your hands shouldn't matter that much as you should be able to stop your bike using at most two fingers anyway with modern brakes, assuming you're using both brakes.
Or just learn to pull both levers and leave them as they are. Also make sure you're using the proper leverage by NOT grabbing the levers too close to the pivots.
Also, don't pay too much mind to the "you only need front brake" school of thought: use both brakes, it's safer and gives you more control over your braking. Applying too much power to the front brake may result in two most dangerous "loss of control" biking situations: over the bars and front wheel skid, both rather unpleasant. While the front brake will indeed provide most of your braking power, the rear brake serves to modulate and control the braking to keep your bike in line and both wheels on the ground. Finally, many modern frames/forks are not designed for the excessive forces of front brake only.
At the same time using your rear brake only is simply inadequate, and may lead to rear wheel skid (but that's less dangerous).
So learn to use both brakes.
Last edited by AdamDZ; 03-06-12 at 08:51 AM.