Kakashi and Iruka from Naruto. For Halloween last year Fenway bought a load of pumpkins for hte house to carve. I did a carving of Kakashi and Iruka.
First step is to sketch out the image with dry erase marker. Then with a steak knife carve out all the lines that you drew, don't punture all the way through! One nice thing about carving pumpkin is that it's easy to get a nice variantion in line width. Now, in places that are "white" or positive carve away the very top layer of pumpkin skin. Finally, for highlights and deatails simply carve deeper into the pumpkin. It's surprisingly easy to shade with pumpkin carvings. If you've ever used a scratchboard then you're using the same technique by carving away at the positive areas and leaving the negitive.