You might enjoy this:
http://www.normankoren.com/makingfineprints1A.html
"Standard monitors have a diagonal to width to height ratio of 5:4:3 (height/width aspect ratio = 0.75). [Thanks to Pythagoras' theorem, diagonal2 = height2 + width2; 52 = 3 2 + 42.] That means that the width is 0.8 times the diagonal and the height is 0.6 times the diagonal. Standard Windows screen resolution choices reflect this 4:3 ratio: 800x600, 1024 x768, 1152x864, 1280 x960 and 1600x1200 (pixels).
Monitors are specified by their diagonal length. Standard sizes are 14, 15, 17, 19 and 21 inches. But there's a rub: CRT manufacturers cheat in specifying the diagonal size! The use the outside dimensions of the picture tube. The opening you see is one inch less than the specified monitor dimensions. My Hitachi 19 inch monitor is 18 inches diagonally. LCD specs are more honest.
You should set your monitor's horizontal and vertical size adjustments for about 0.1 inch margins-- about as large as you can without cutting off the edges. Image sizes are shown in the table below.
You should set screen resolution for between 72 and 100 pixels per inch. If you set it for less than 72 pixels per inch, you won't be making use of your monitor's capabilities-- your image will have less detail than it should. If you set it for more than 100 dpi, you may be sending more detail than your monitor or eyes can resolve. To adjust screen resolution, right-click on the Windows wallpaper (the background outside any open windows), then click on Properties, Settings. Suggested monitor resolution settings are shown in the table below-- recommendations are in boldface (the higher resolution, 90+ ppi, is for younger eyes).
I recommend at least a 17 inch monitor and at least 1024x768 resolution. If you increase resolution and fonts are too small, you can adjust them by right-clicking on the Windows wallpaper, then clicking on Properties, Appearance. Details depend on the operating system."