Despite the fact that more and more Internet users switch to broadband every year, a large part of the web's population continues to be running on good old dialup connections. It is therefore unwise to count them out of the equation when you're designing your website, and a very major consideration we must make for dialup users may be the loading time of your site.
Generally, all the text on your own website will be loaded in a very short time even on a dialup connection - making it easy for your customers. At fault of slow-loading sites is principally large images on your internet site, and it is very important to strike a delicate balance between using just enough images to attract your users rather than to bog down the entire loading time of your website.
You should also go to a greater length and optimize every image on your site to make sure it loads in the least time possible. What I really mean is by using image editing software to eliminate unnecessary information on your pictures, and thereby effectively reducing the file size of your image without affecting its appearance.
If you own Photoshop, it will be obvious to you that whenever you save an image as a JPEG file, a dialog box appears and lets you choose the "quality" of the JPEG image -- normally a setting of 8 to 10 is good enough as it will preserve the quality of your image while saving it at a little file size. If you do not have Photoshop, there are many free image compressors online that you can download and use to reduce your image's file size.
On the other hand, you can choose to save your images in PNG format to get the very best quality at the least file size. You can also save your valuable images in GIF format -- the image editing software clips away all of the color information not found in your image, hence providing you the smallest file size possible. But saving in GIF format will often compromise the appearance of your image, so make your choice wisely!