I understand that it is very tempting after you have captured those special photos for yourself or your clients to want to crop it to make it perfect. Unfortunately if you open it in photoshop draw a box around it and hit crop it is not going to print as a 4×6, 5×7, or 8×10 without further cropping! It is a physical impossibility. This being said, I would like to give everyone a few options. Do not crop your images until you figure out what size you or your customer wants, and then crop it to those dimensions. This is easy to do in CS6 as it gives you the “normal” print sizes as options. In CS5 and below it is as simple as putting the dimensions in the cropping tool and sizing to your hearts content. As you can probably tell I work in a photo lab and this is a subject that comes up frequently.