L.T.
I HIGHLY recommend Village Montessori School. It is in Roswell, but just on the west edge. It is near Hwy 92 and Mabry Rd.
Our daughter has been attending there since she was 2. She is now in their elementary program. Even if you just go there for preschool, I feel that the Montessori method really is great for all children. It helps prepare them for the "real world" and teaches life-long skills.
The Montessori method is based on a child's natural tendencies— to explore their surroundings, move around, socialize with a group, etc. It teaches (by experience) self-control, hard work, the positive feeling of accomplishement, and decision making.
If you aren't familiar with it, there are some great resources on the web. You might look at:
http://www.montessori-ami.org
http://www.montessori.edu
http://www.montessori.org
Also, village's web site is: http://vmschool.com
Good luck in your search and welcome to east cobb!
L.