I spend more on paint per sq. ft. then I do drywall when doing a new room.
If that insulation has paper on it then take off the plastic and hang the drywall. If you left it up you'll have a double vaper barrier. If you can get them down there 12' sheets hang faster and there's less seams.
You alway start hanging at the top of the wall to it's tight against the ceiling and the bottom piece needs to sitting 1/2 up off the floor so it can not wick up moisture.
PS the ceiling always gets hung first before the walls.
Also a basement with no windows is totaly illegal to use as a living space. There has to two points of egress in case of fire.
http://www.basementanswers.com/basement_egress_window_wells/pages/content/irc_2000_egress_code.html