I you're talking about making the pattern to cut the puzzle pieces then take a look at Steve's blog. He has a set of puzzles in standard sizes (I think it's $7 for a bunch of patterns) and a video on how to make a puzzle from a photograph or other picture.
If you're talking about your friend making the picture to put on the face of the puzzle...how good a friend? Maybe trade a couple of finished puzzles for the artwork?