The Museum of Modern Art presents this classroom or group activity for making stencil portraits. Requires Adobe Reader. [PDF]

From the Holliston Historical Society this is "Stenciling: Short History of a Very Long Tradition", which goes into detail about the historical evolution of the use of the stencil in arts and crafts.

The St. Louis Public Library presents this informative description of methods for stenciling on different surfaces. Books on the topic are linked to the page as well.