Hi, Ron. Just look down this board to a series of posts starting on 4/30--and a whole slew of other prior posts on this subject if you go down far enough.
For what it's worth, one neat installation tip is to rip a 2x4 to the same angle as the back of the crown molding and slightly smaller. Screw this to the studs flush to the walls and ceiling. This gives you a great nailer for installation of the molding. Another tip is to prefinish it as much as possible before you install it. Then all you have to do after it is mounted is touch up where you have cut and nailed it. Don't forget that you miter outside corners and cope inside corners and back cutting makes for a tighter joint.