This is a great halloween project to do with kids because you don't have to cut the gourd open.  That means there is no gourd dust, or sharp blades to deal with.  You will need:

Gourds with a "ghosty" shape, like club gourds or swan necks

Fine sandpaper

A tack, small nail, or small hand drill

An eye hook

A length of nylon line (fishing line works great)

White exterior acrylic latex paint (get high quality paint with a hightitanium dioxide content so your gourds last)

Black acrylic paint for the features

Spray can of protective glaze varnish (Krylon triple thick glaze works well)

STEPS:

1.  Sand your gourd lightly with the sandpaper so your white paint sticks.

2.  Start a small hole in the top with your tack or small nail and then screw the eye hook in, tightening all the way down.

3.  Cut a length of nylon line and insert through the eye hook to make a hanger.

4.  Now give it a good first coat with your white latex paint and let dry (you can speed this up with a hairdryer).

5.  Give it another coat of white and let dry.

5.  Paint on the features using black acrylic.  It's always good to practice your design on paper first. Let them dry then do it again to give the black depth.

6.  Spray with 2 or 3 coats of protective glaze and let dry.

The whole process can be done in one afternoon depending on how fast the paint drys in between steps.

Take care of your ghosts in between seasons by wiping them off with a damp cloth and storing them in a dry place.

GOOD LUCK AND HAVE FUN