You'll need a software that supports vectorizing. The one I use is Acme TraceArt, it's shareware..
You'll have to import your image, and vectorize it within. You'll want a picture with the best contrast possible between colors to better define the contours. Pictures with too many colors are just too complicated and require higher end software to detect all the various contours automatically.
This traceArt program will work perfectly for bold pictures (black/white with thick lines).
Heres a link to some info on it....
and here's the direct link for the shareware download...
hope this helps...