There are a number of ways to get images to place on your site, based on what you are looking for. You can use a digital camera to take pictures, and then upload the pictures to be placed on your pages. You can also use a scanner to scan pictures that can be uploaded, and you can also purchase large volumes of clip-art that are available on cd's and use these images on your site. SpinSite also offers their own image library. On your Uploads page, click on 'Import Image from SpinSite Library'.
You can also find thousands of images on the Internet. You need to be careful, however, that you have the "right" to use the images that you find. Many images are "public domain" and can be used freely. Other images are free for you to use on your personal site, but need to be licensed for use on a business site. Finally there are images that must be licensed period. The best way to get started is to search on "clip art" or "free images" in your search engine.