You should enter the GPA that appears on your high school transcript. In some states, this will be weighted, in others it will not. Colleges are aware of the difference and often recalcuate GPAs according to their admission office policies.
Each high school usually decides whether to give more value to honors and/or AP or IB courses than normal. For example: if you received a B+ or 3.3 in an honors course it might have an additional .5 added to it giving it a weighted” value of 3.8. If your school does, this then on the CommonApp or other applications you would indicate that your GPA is “Weighted””