These beautiful scans from a 1940 issue of Popular Science were part of the original publicity campaign for Disney's Pinocchio. The main article is a tutorial explaining how to make a Pinocchio marionette similar to the one used as a reference model by Disney animators while they were making the film.

From the article:

Pinocchio, the wistful puppet created by Geppetto, the wood carver, in Walt Disney’s second full-length production, is an inviting subject for either a homemade puppet or an amusing and companionable little doll. The accompanying illustrations show how to go about making one patterned after the original, which was created by the Disney model department as an inspiration to the animators drawing Pinocchio. 

The scans of this article are quite large so click the thumbnails below to download full size versions from Flickr:

The article suggests either carving Pinocchio's head from soft white pine or molding and casting the head in plastic wood, but unfortunately (well, probably fortunately) the Plastic Wood used in the 1940s is no longer available because of it's extremely toxicity and modern plastic wood doesn't work very well.

The best and easiest casting substitute for something like this is probably papier mache. More advanced or adventurous puppet builders could try making a silicone mold and casting the head in light weight resin. Two great books that explain molding and casting in depth are The Prop Builder's Molding & Casting Handbook and Figure Making Can Be Fun. The UK's Blind Summit Theatre has a good page with an overview of how to cast resin puppet heads as well.

And what can you do with your Pinocchio when he's finished? How about something like this:

Pinocchio plans provided via Modern Mechanix.