This is best site I have found for the beginner in the art of silk screening.
Silk-screening, or screen-printing, is a technique for printing images through a piece of fabric using a stencil or mask. It's an adaptable technique which can be used successfully by beginners as well as very experienced artists.
Here's a couple of websites with how-to info.
Dharma Trading Co is a great place for supplies,
and there's a tutorial on the site, too.
Good luck and enjoy.