Here's a list of stencil tutorials that I used to help me get started. There's a heap more out on the net, but these are some of my faves. Enjoy!
This Stencil Graffiti tutorial is a fantastic and in-depth tute on designing, cutting, and spraying stencils.If you've always wondered how to make a stencil of Dick Cheney using Photoshop, today's your lucky day - here's a tutorial.
Another Photoshop tutorial, but this time with more appealing subject matter - Blondie. Part 2 of this tutorial is about cutting and stencil design and putting it onto a t-shirt.
From Black Kitty blog, a very cool little tute on doing your own stencil portrait. A great tute for beginners.
Here's a tute on spraying a multi-colored stencil, and another with lots of information about stenciling materials, and photos of stencils to inspire you.
Also check-out You Tube, which has a heap of stencil tutorials.
Banksy - Maid in London.