Go check out MAKE’s Halloween blog for plenty of cool Halloween projects–cool pumpkin carving stencils, homemade costumes, DIY scary sound generators, and more. Check out the whole site while you’re there. Good stuff.
The Pumpkin Lady shares lots of cool easy-to-use stencils, including this nifty Shakespeare design:

If you are a socially-challenged misfit with plenty of spare time, go to Raven’s Blight to download PDF how-to’s for constructing paper Halloween toys, like this “Moving Sculpture.”
Halloween Web has all of your fake-blood-needs covered, including this classic recipe:
Homemade Fake Blood
1 c. Karo Syrup
1 Tbsp Water
2 Tbsp Red Food Coloring
1 tsp Yellow Food Coloring
Mix together in a mixing bowl and you’re done. Try adding blue or yellow for a different shade.
