Go to page 17 of the AADSAD Instructions:
http://www.adea.org/webdocs/AADSAS/appAADSASInstructions.pdf
It explains everything.
You pretty much add in all the college level courses you've taken in your entire life (including but not limited to classes you've repeated, classes you've failed even if you retook them, and classes taken overseas), and calculate your GPA.
I hope this comes to use for a lot of you because I wish I knew. If I did, I wouldn't have taken repeats as light as I did.
Good luck, y'all.