Here is the direct link. http://www.nvrqs.go.kr/PopuoUrl/201105/popup_20110504_eng.html
You'll have to micro chip your pet, provide a health certificate, and if they show that they are rabies free, a 1 day quarantine. It's a hassle, but not a big deal.
New Zealand is also free of rabies, their quarantine policy for bringing dogs from regions with rabies is much stricter.
To show that your dog is free of rabies, that test needs to be completed 3 months before you get to Korea. In the U.S., there is only 1 lab that does this. You would take your dog to a vet for a blood sample, then that blood would be picked up by an intermediary lab. The intermediary lab would pack it in dry ice, then express mail it to the lab in Kansas. The lab in Kansas (the only internationally approved lab in the U.S.), would take about 4 weeks to complete the test. If the test shows that the antibody level is .5 IU/ml or greater, then the 3 month (in-country) quarantine starts from that date.
Add these things up: Vet visit + Intermediary lab + Shipping to the lab in Kansas + 1 month for the rabies test + 3 month (in-country) quarantine. I'd say it's at least 4.5 months. This is assuming your dog's shots are current, or you'll have to wait 30 days before you can even start the antibody test. That would add another month, bringing the total to 5.5 months. If your pup's antibody tests lower, you'll have to restart the process.
I verified all of the info with the Korean Quarantine Service.