Jeanne, visit grammatjr here on the board, she has written a book about this process, and has a lot of info on her blog. I think she had a tutorial at one time, but not sure if it's still there. The book is on CD only but I found it very helpful and easy to follow. It has lots of patterns plus directions for using your own patterns like I did here.
You can use photographs, but I used a coloring book drawing for this particular image.