Go ahead and bring the image down to a size you would like to display it at. Here I've picked 4x5.3 inches. Keep resolution at 72 dpi since all monitors display at 72 dpi. If you choose a dpi of 144, then the image will be displayed at twice the size you specify since the monitor is unable to show 144 dpi of resolution. Also, keep the "Resample Image" and "Constrain Proportions" boxes clicked.