Once you have decided on the images that you need on your site, make sure that it is optimized for the web. They should be in the gif or jpeg format. You can also minimize the size of the image by choosing the number of colors you need, from the color palette. The less the colors you choose, the less the size of the image. You can also use online tools like gifwizard to optimize your images or to get a recommendation on how to cut down the size of an image.