This tutorial gives you some easy instructions on how to get a decent vectory style image.

- First choose an image to start off with.
http://img.photobucket.com/albums/v430/Karant/P1000970.jpg
(I chose a picture of myself.)

- Next go to Filter > Artistic > Cutout, and adjust it to your likings.

This is what I got:
http://img.photobucket.com/albums/v430/Karant/vectorme.jpg

how big will this come out in the sig?

it'll come out the same size that you vector; when u vector that way it doesn't change the size of anything just the effects of the picture are changed.