As you choose colors for you page, you see a sample of your choice in a test box. The background image feature is another attribute of the BODY tag. This is an HTML 3.0 feature that is not supported in all browsers. The background attribute refers to the URL of an image, and tiles the page with this image. The image itself may be quite small, but it will be repeated over your entire page to create what looks like a single seamless image.
Some pages look like they have a background covering only part of the page.
If you like Jelane's style, then you're in luck. This collection includes sets of backgrounds, lines, buttons and arrows - this can save you from spending a lot of time looking for images that go well together. If you find images that you like and might have a use for later, save them to a disk. Remember that if you choose a dark background and light text, your text will not show if it's printed on paper. If you expect people to be printing your documents, use a dark text color.