Actually, how I should have said it was to use the full size image as it comes out of the camera to do your editing on. Then, after you have cropped, color corrected, re-sized, sharpened, etc., then change it to 100 dpi (I prefer 100 over 72) with a profile of sRGB (I work in AdobeRGB until I'm ready to save). Also, make sure you are at 8 bit in case your camera is set to save in 16 bit (it probably isn't). You may also have to sharpen a bit more at full size than you normally would because you lose sharpness when you reduce size. Also, there are other formats besides jpg that might be better to save in for a small images like this.
And after all the work you do and no matter how good it looks to you... it's still only going to look as good as the video card and monitor of the person viewing it allows.
Mike