Peter E , Sep 22, 2011; 12:08 a.m.
I follow your crop approach except that I use Lightroom. In most cases I don't take the images into Photoshop. In Photoshop you can crop with or without changing pixel resolution assuming that is what you mean by reassigning pixels. In either case, the cropped image contains less information regardless of pixel resolution. And I don't leave it up to the printer to crop my images. I crop to the aspect ratio that is appropriate for the paper size. For some images, I create differently cropped versions (saved as tiff files then jpg for sending off to a commercial printer) for different aspect ratios. That's all very straightforward in LR especially if you print directly from LR.