OK for starters, lowering the bike does not drastically effect your handling, you will only really notice any difference on the track (which you wont notice that much of a difference) For street riding, do what you want. Its not going to make a difference if the bike is even or not. The bike is actually higher in the rear, so when you sit on it, its even. If you make even when you are off it, then it will sag in the rear when riding. So if you dropped the rear and inch (1 inch, would mean 3/8" extension of suspension links, or dog bones) then I would lower the front anywhere from .5-.75" that will set you about perfect. You dont really have to measure too much to lower the rear, because you have to put bolts through a hole, so they have to be pretty close. But the front, you want your measurements to be EXACT, or else your bike will pull. So do this with precision. If your a beginner at lowering bikes, then use two people to do it. You need one to hold the front end up while the other loosens the pinch bolts.
Scott