I'm not a PC alum, but a close friend is, so I'm getting all this second-hand, so take it with a grain of salt. Getting into the Peace Corps is very competitive these days, so I would imagine that it would be very difficult (though apparently not impossible, according to the website) to be accepted without a college degree. My friend also says that they favor people with "practical" degrees--public health, engineering, things of that nature. I would definitely suggest going to college first, both to give yourself some experience in living independently in a country where you won't have to boil drinking water, poop in a hole, speak exclusively in a foreign language, etc and also to build your educational resources.