As a generalization, almost all the schools are fairly equivalent. There are die hard parent advocates at each school. The differences become more evident at the high school level. As you already know, the biggest effect you an have on your kids is to spend time reading to and with them, discussing books, etc. What you do at home has an effect.
This is a fabulous area to raise a family. Our kids loved living here.
They usually try to get back within 24 hours. Let me know if I can be of any help with your home search or getting to know the area. I have lots of great information on my online relocation magazine as well that you may find very useful.
Larry is right about zip codes having absolutely no meaning in regards to school assignments. I have a link to the school assignment map along with information about each of the Chapel Hill/Carrboro City schools on my website
I also have some photos of the schools. Even though a school is only a building sometimes it's helpful to have an idea of what the school looks like when researching the schools.
Within Orange County depending on where you live in the 27516 zip code the schools could be:
Elementary: Morris Grove, McDougal, Seawell, F.P.Graham, Carrboro (Grady Brown - Orange County not part of the Chapel Hill school system),
Middle: Smith, McDougal, Grey Culbreth, Scroggs,(Standford - Orange County not part of the Chapel Hill school system),
High: Chapel Hill, East Chapel Hill, Carrboro, (Cedar Ridge - Orange County not part of the Chapel Hill school system),
If you are focused on specific schools then searching by zip code is not going to be effective.
I specialize in buyer side brokering and would be happy to help you if you'd like assistance. Feel free to contact me directly through my profile here on Trulia.