It's hot, very hot in the summertime, because a warm, humid air mass descends on Atlanta in May and usually just squats there till the end of August, sometimes later. Winters are agreeably short -- and when things get icy, Atlanta just shuts down and waits a day or two, and it passes. The rainiest months are October and September. If you are sensitive to the sun, prepare to get used to the idea of wearing light hats and clothing outdoors.
If you like the outdoors, you'll be pleased to know that you're not far from good hiking in some very old mountains. Georgia also has a number of fresh water lakes where one can swim or go pleasure boating.
Housing will be your biggest expense. Apartments are easy to find, but quite costly for what you get. With a range of sizes available, apartments can often provide housing nearest your workplace.
You should be able to rent a home for around $1200-1500 per month. You will need [not wish you had, but NEED] an automobile, and you'll need to adapt to using it often -- get used to the idea of driving everywhere you go.
If you prefer a quiet life, try to rent a home. We get loud over here. Apartments can be loud places to live. Sorry, I should point out that "a home" in this context means a free-standing house, almost always a single-family dwelling.