The short answer, have someone replace the power steering belt.
Long answer, if the belt is tight it maybe glazed,old,hard,cracked and it's slipping when a load is applied to it, when your turning. The slippage results in heat and smoke. If it has been permitted to run in this condition very long it will harm the pulley grooves to a point that future belt service life will not be very good. I hope the seal on the p/s pump is not leaking as it would require replacement.
Best answer, replace all belts.
As an after thought make sure the p/s pump turns freely when you have the belt off.
There should be little or no resistance to your hand turning it. If there is it's toast.
That's doubtful but check anyway....Hope this helps...