The only way you can be sure an image will fit on lower resolution monitors is to test it. To create professional images for the web you will probably need an image editing program. For images to download quickly they need to have small file sizes. Sizes of 2k to 15k are considered small and practical for the web. An entire web page should be no more than 30-50k in most situations.
Web designers can change the file sizes of images by decreasing their dimensions.
An image that is 100x100 pixels will be smaller and download faster than a 320x240 pixel image. Visitor Access Keep in mind where your visitors are located and how they connect to the Internet. If all your prospective visitors are coming from the UI campus computer labs then access times should be quick and the number of images on one page should not pose significant download problems. If you want students to access your site from home and they have 28.8 or 14.4 modems, you need to carefully consider the size of your images. Suppose you want visitors from rural Washington and Idaho, along with colleagues from Japan and Poland, to see your site.