That's alot of work to draw, scan then vectorize. If they are drawings, I'd say just make sure he draws LARGE. Usually you get the best results if you draw the cartoons larger than the size you intend to print at. That way shrinking down doesn't distort anything (but scaling up does).
When the drawing is in PS, then just make sure it's all done at 300 dpi. You'll be happy with the results...