This article by Libby Lehman describes how to make and attach a sleeve.
http://www.quilts.com/sleeeves.pdf
I can't speak to the issue of whether the show wants the bottom or top of the sleeve at 80". Asking them would be the best way to find out.
Notice that the sleeve does not need to be turned to be "right side out" since the raw edges of the seam will be against the quilt. Also, the directions allow the sleeve to be a little loose (rather than completely flat) to accommodate the rod.