Better, not to guide them at all. Line up your shot with your helicopter first, seat jump, fire, and then seat jump back. I've killed / burned thousands of walkers, tanks, and infantry this way. I would dare say, I've probably killed more 2142 vehicles with the TV guided missle than anyone else in the world.
Yes, I can steer, and do, usually against air targets at long range. To have a good ping is important. But its superior to come up behind your target, aim with the chopper, seat jump, fire and forget.
I don't need no stinking teammate in my chopper, and when they do jump in, I usually auger the chopper face first into the ground before jumping out of course, and getting me a fresh copilotless chopper.
But then I just roll like that
http://choppergirl.air-war.org
CHOPPERGIRL