My sister-in-law lives in Marietta and loves the daycare she uses. She's not in that zipcode, though. Is that a Marietta zipcode? The daycare she uses is called Kids-R-Kids, but I'll have to get the exact location because there are about 5 in Marietta, and each one is very different.
About moving to the area - it'll be hard leaving friends and family, but it really is nice here. We moved here last year when I was (9 months) pregnant with my first....that was very difficult because I had no friends or family here to help out. Since then, though, I've made quite a few friends by joining some playgroups. It seems like most of the moms are also new to the area, and they're all so nice! Everyone else here is overall pretty nice, too. It's a much more laid back place than Chicago.
Once you get settled in, take a look at the playgroups. One can be found on www.meetup.com (do a search for SAHM groups, and then your city). Another one is www.alpharettaplaygroup.com, which is moms from the northern GA area.
Good luck with your move. If you'll be in the area for a while, I'd suggest renting for a year so you can determine where you'd really like to live.