For Wake county schools, go to
www.wcpss.net, and for Johnston County, go to
www.johnston.k12.nc.us. To compare test scores for nc schools, go to
www.ncreportcards.org.
When we first relocated here, I taught in Wake county as a regular ed middle school teacher, and I was impressed with the resources the special ed teachers provided us for our kids with IEPs. At my school (can't speak for others) they were not overloaded, and able to provide support as needed.
Clayton is a great town - I would also recommend looking at Wake Forest and Holly Springs if you want a small town close to the amenities of the city. My kids are in elementary school and preschool in Wake Forest, and we couldn't be happier. Of course, Raleigh has some great family neighborhoods, too, so depending upon where you'll be working, you may want to look in Raleigh, too. Feel free to pm me with specifics, and good luck as you plan your move!