The UGA Admissions Office blog is the best I’ve seen with regular updates throughout the application cycle, proactively sending out updates re: key dates, target decision dates/times. It also includes an active Q&A in the comment section which is reviewed/updated frequently throughout the day.
This FAQ link on the blog site includes the UGA Admissions Office calculation method: http://ugaadmissions.blogspot.com/2013/11/calculating-uga-gpa.html