Motorman- I've had the best results with film that doesn't have adhesive on it by spraying the film on one side with 3M-77 adhesive. Let it dry for a couple of minutes so it's NOT agressively tacky. Handling almost requires two people, but if you do half the wing at a time one person can handle it with practice.
The wing should be blocked up off the table. Do the bottom first. Gently work out from the center of the panel pushing the covering out ahead of the iron and going in an elliptical motion until you get all the covering out to the edges. Fold the covering around both the LE and TE at least half an inch. When both sides have been covered seal the edges with gold(foam safe)CyA glue.
It's best to cover the whole wing, built in one piece, before installing the fuselage. Interrupting the covering at the fuse side sets up a big high stress area that can fracture any wood covering or the foam(if unsheeted).
If you're looking for a contest finish cover the foam wing with paper(silkspan or used exam table paper!)not. Then apply a couple of thin coats of 50% thinned, water-based urethane varnish- Varathane or Carver-Tripp are well-tested, other haven't been reliably fuel/oil resistant. Fill the suface with thinned light weight spachle. Sand it all off and repeat as needed to level the finish. Then apply the film. For a paint job the covering will need to quick build auto primer. Again, apply a solid coat and sand almost all of it off. Repeat until the surface it level. Apply a thin white base coat(or use white primer if you come across it) and finish as desired.
Good luck.