Before you upload an image to your Web Graphics library, read our article " Photos and Web Graphics: What's the Difference? "
Navigate to the Control Panel > Website Tab > Setup > Web Graphics.
Click Add Web Graphic to add a new image to the library
Choose the file from your device, and optionally, enter a title. Choose a folder from the dropdown menu if you've created folders to help organize your graphics. If you haven't created any folders, all graphics are saved to the same default folder.