Seconded
Which spoil sport merged Kitster's thread into this one?
These are far too good to get lost in here, especially as he is trying to make a few quid as well (and worth every penny).
just been looking everywhere for this.
Using vectors is really simple once you get going, and very useful. Try putting an image into Adobe Illustrator and trace round it using the pen tool, you'll quickly get the hang of paths etc.,
CHE pretty much sums it up Import your scan into PS or Illustrator - leave the scan as the top layer - and take the opacity to 50%, and select 'Multiply' as layer style, then build up layers of vectors to make the image.
I personally make paths in Photoshop and export them, as it seems much easier for me.
It is a good idea to pick up a book on Illustrator (something like the Illustrator Bible) and keep it at hand - although they are both adobe - they are annoyingly different to use - and just the smallest glitch can set you back hours with no reference. But if you know pS, you will pick it up in no time i'm sure.