BeerAdvocate's site has a feature called Beerfly which is pretty danged good for finding craft beer pretty much anywhere in the US with reviews to boot.
All I know about South Georgia is Columbus, GA, which I think will be on your way to PCB. Boo's Liquor has the best selection and prices for its size but it is small. They are recommended because they are right off of I85 and they are great people. For a bigger (read huge) selection but higher prices and less personality there is Wine and Spirits Shop of Bradley Park.
The local brewery is called The Cannon and it is in Columbus' small but very nice downtown main street. The beers are nothing special but worth getting the flight if you want to taste the local brewery scene. Their non-alcoholic Root Beer, however, is one of the best I have ever tasted. It comes on the flight.
There are several bars right around The Cannon and I would recommend The Loft. The Loft has a decent selection of taps and bottles, nothing amazing but the setting is great, the chances of catching good live music very high and the food is the best bar food in Columbus.
For food in Columbus, well, there's a few good ones but I highly recommend Chili Thai although there is nothing to speak of beer-wise there.
Finally, the Mellow Mushroom right down from Chili Thai has one of the better beer selections I've found in a MM and they staff with beer nerds. Cannot go wrong with MM for good beer and quick food.
So, there's Columbus for you, it's about the only thing that happens between Atlanta and PCB except for a tiny little town called Eufalah which isn't going to deliver any beer nirvana but there is a restaurant called the Cajun Corner that you will drive right by that cannot be beat for some decent cajun food in the area. Eufalah itself is very historic and, IINM, right around now they are doing their Pilgrimage event where all these old plantation houses are open housed and thousands of people turn out for that so you may have to stop there anyway thanks to the traffic.
As many times I went to PCB during my 14 month stay in Columbus I always brought my own beer and scuba diving was the focus so there wasn't too much surface exploration I did down there. The best beer I found was at, ahem, Mellow Mushroom but boy do they have big beer on tap there. Lots of 9%-12% beer flowing on the taps at that MM. PCB is a very nice place though and I'm certain someone can tell you where the goods are in that fine city.
Hope that helps.
