Hi, I am very new to photography and I have a basic question that I hope somebody would be willing to help me with. I just bought a Nikon D40 and I took some pictures in the Auto Focus mode. When I went to have them printed, which I was ordering online at CVS, I was warned after I uploaded the pictures that I should not print at this resolution. I am not sure what to do or what that means. How do I take a picture and blow it up? Thanks so much and I would love advice and ideas about how I can learn more about my new camera.