I don't really think all that much of going to Dahlonega, perhaps that's a recommendation from your friends. There's a nice little town square with a general store and a nice sandwich and soup shop next to it, otherwise it doesn't offer all that much, it's close to Atlanta, and it's not at all that much elevation so the temps won't be that different. And in my mind, it doesn't really give you all that much of a flavor of North Georgia.
Elijay might be another option you would want to look at.
However, I strongly recommend Rabun County if you want to get higher up, see beautiful scenery, and be close to both Tallulah Gorge and to the Chattooga River for rafting.
My wife had said that Old Edwards Inn had bought a property in downtown Clayton, and that they were building a hotel. I am not sure they finished it or not. You might want to use the Google machine to look for places to stay in or around Clayton, other than what I wrote in my previous post.
Lots of nice places to eat in Clayton. However, you need to get your redneck on and experience some real Southern eating while you're up here. You could have a really nice meal some time at Waterfall just off of Clayton. It used to be only private, but I understand you can get a meal there now even if you don't "belong". Check out the view! Update: The Farmhouse is a farm to table restaurant that recently moved into the Waterfall Country Club. It is open to the public and the chef is great. You could probably go to the Farmhouse and then go up to Waterfall afterwards and just check out the view.
The Farmhouse at Waterfall ClubDining at Waterfall Club Lake BurtonMy pics from Farmhouse Restaurant:

Signature Par 3 at Waterfall Club, 210-foot drop that goes over a waterfall, a slice of Lake Burton and surrounding mountains in background. Picture doesn't do it justice

18th hole at Waterfall with beautiful Lake Burton in background

Pics (not mine, I was eating at the restaurant up top) of the Lake Burton 100th birthday celebration fireworks from Waterfall Club:


The guy who runs The Farmhouse also has a great take-out restaurant just across Hwy 76 and up a bit. If you want to have something tasty to take home, I would strongly recommend it. His BBQ is also supposed to be excellent.
The Farmhouse Market Lake BurtonAnother good artery clogger is a bit further down on the south side of Lake Burton at Batesville General Store. You can get some definite biscuit poisoning there. It's a good mix of locals and visitors.
http://www.scenic197.com/index.php?option=com_content&view=article&id=52&Itemid=74I would also go to LaPrade's marina and dine upstairs on the open air deck, especially if they have music playing on a Friday or a Saturday evening. Alternatively, go next door to Milton Park Pizza and either eat on the picnic table or drag your pizza and excellent (but pricey) salad next door and sit out on the deck at LaPrade's.
LaPrade's MarinaMy pic from LaPrades upper deck:

Don't bother with eating indoors at the Chophouse restaurant upstairs.
One of my buddies who is retired and lives on the lake part time really likes TB & J's on 197, named for Tyler Boone and his wife Jessica. "Really nice people and excellent BBQ". Right across the street from Mr. Bud's Campground. Got the flavor?
My wife and son and my friend also like Fortify Pi in Clayton.
I have eaten there once, I thought it was reasonable.
Fortify PiFor Pizza I prefer, as above:
Milton Park PizzaAnother very quaint spot to grab a sandwich and some minnows and an ice cream bar is Anchorage Marina. My photo from yesterday in the H&F forum was from the dock there.
Anchorage Marina Lake BurtonRent a boat from either Marina and check out how the multimillionaires' vacation (including Nick Saban and my Residency roommate, etc.)
The water in the lake is really clean. Family reunion pic:

There are tons of dining experiences in Clayton now. It is becoming a bit of a retirement spot. The only one we used to go to was Grapes and Beans for lunch/brunch.
Grapes and BeansWhether or not you stay there, it is fun and interesting to have a family-style meal at the Dillard House, as in the post above. I think you've got a few choices there.
Let me know what other questions you have, I will come up with more. No reason to eat at a chain restaurant up there.