Prevent damage by sizing walls


I was thinking of wallpapering several rooms in my house and installing a few borders in others. But after talking with some friends who have removed wallpaper from their houses I think I might not do it. As they removed the paper they ruined their walls. The paper facing on the drywall was ripped off! Is there a way to prevent this? What can my friends do to restore their drywall?

Darcey R., Brookville, IN