You might start by making sure the wheel isn't out-of-true so far that your tire casing is getting sliced open by the brake pads. If the out-of-trueness is really bad, you should get that fixed by your LBS, because the wheel's rim is a part of the brake system (namely, the rotor).
With brakes that simply howl when they're applied, you may need to adjust the alignment of the pads so that the front end of the pad hits first, a "toe-in" position. If your pads are too worn, this may not be a good idea since it would concentrate wear on the already-thin front end of your pads, eventually resulting in metal-on-metal contact when all the pad material was worn away. Your LBS (local bike shop) can give you an opinion if you show it to them, and you can price the new pads at the same time.
Changing the alignment on V-brakes is usually done by loosening the fitting that holds the brake pad a little, angling the pad as desired, and tightening down the fitting in that position. Since the pads adjust in four directions at once when loosened, it may take a bit of patience, and you will want to do only one pad at a time so you have a reference for how the hardware stack is set up.