I've read at various places that when an uncircumcised person is erect, that his foreskin is retracted over the head. However, when I'm erect, my head is not exposed unless I pull the foreskin back over my head manuelly. I guess my question is when my foreskin will retract over my head automatically when erect, or if there is something that I should do to make it retract automatically.
No, not at all. Nothing hurts or seems wrong, it just simply doesn't retract over the head by itself when I get an erection, I have to pull the foreskin over the head manuelly.
Most don't completely retract by themselves. It's perfectly OK to do so manually. If you were penetrating a vagina (without a condom), it generally would retract upon insertion (unless of couse you can't retract at all in the first place).