Most monitors display images at 72 pixels per inch. Some displays are able to display 96 pixels per inch. So, if you want to see how big the image will appear on a computer monitor, you can change the RESOLUTION in the DOCUMENT SIZE section of the dialogue box to that of the computer monitor ~ namely 72 pixels per inch. If you do make this change, please UNCHECK the RESAMPLE BOX. With the RESAMPLE BOX unchecked, change the RESOLUTION from 240 pixels/inch to 72 pixels/inch. Your dialogue box should look like mine above, except your RESAMPLE IMAGE box is unchecked. You can now click on OK to committ your changes.

Once your image is resized, it is important to sharpen your downsized image to restore the sharpness that is lost during the downsizing process. I typically use the Unsharp Mask at settings of 0 threshold, radius of 0.8 and an amount from 50 to 100.