Better Homes & Gardens has a great Jack O Lantern Pumpkin Stencil Maker. It lets you pick the eyes, nose and mouth of your Halloween pumpkin from many options and then print a stencil to create your Jack O Lantern! Very cute.

Family Fun also has a a section on Jack O Lantern Ideas and carving patterns here.

Pumpkin Masters has some free pumpkin carving patterns here, and Kraft has some here.

The World Wildlife Foundation has some great nature-themed pumpkin stencils here.

Hersheys has some nice pumpkin stencils here.

And finally, Spookmaster has free Halloween Pumpkin Carving Patterns here.