Labor hurts. How much it hurts depends on your labor, your expections (if you think it's going to horrible, it will be horrible), your preparation (tension can increase pain, so learning about what to expect can help, as can relaxation/breathing techniques), and hospital policies. (Being confined to bed on a monitor with an IV can make things harder to cope with than if you are allowed/encouraged to move around, labor in water, etc.)
Different women will describe the pain differently, (and it's really nothing like you've ever experienced...) but it's probably best described as really intense cramps. (Like very severe period cramps.) It can be in your back, or your belly, or both (at different times. Early labor is usually felt in the back. Later on it moves to the belly.) The GOOD thing is that they are intermittent. It hurts for about a minute -- and then you get a break of several minutes before the pain returns. And, of course, if the pain IS more than you can cope with, there are many, quite safe interventions that can help. So don't feel that a c-section is your only option. (If you had a c-section, you could get a spinal or epidural beforehand. That same epidural can be used in a vaginal delivery if desired.)
Tearing (or an episiotomy -- where the doctor cuts your perineum rather than allowing you to tear) isn't common if labor is managed correctly, but it does happen. (And is, unfortunatley, more common in epidural births, since it's harder to control your pushing, and forceps are more likely to be needed -- and forceps usually requrie an episiotomy. And no, you don't feel it. Usually, by the time the tear or cut happens, baby's head is pushing against the perineum, and it tends to cause the area to go numb. If you do feel it, it's not very noticable. (Pushing the baby out DOES hurt -- unless you have a strong epidural, in which case you won't feel the cut either.) When the doctor repairs the tear/cut, if you are not completely numb he will use a local anesthesia. There is some pain/discomfort afterwards, as it heals, but it's no worse (and usually much less) than the pain of a c-section incision.
Do some reading on natural childbirth. Take a class. Even if you decide on an epidural, educating yourself about the process and what to expect can only be a good thing.