Adding images to the design after adding them to WordPress…

I have a website where each page has different images as part of the design. The images should be able to be edited by the website owner, without using Photoshop. What I am wanting to ask is how can I add all of the images into WordPress, and when I comes time to add those images to the website, is there a way to add them by using something like a variable? Please see this example for more of an idea. Thanks in advance.