1. Click on Media in the navigation bar.
2. Click on 'Add Media' link or the 'Add Media' button as shown in the image below:
3. In the 'Add Media' options displayed, select the option - 'A Site Category' and select the appropriate category from the drop down.
4. Click on 'Upload Image'. You can select multiple images to upload at the same time.
5. Provide an appropriate Title and Description for your image.
6. Click on 'Save Media'. Your image will now be added to the appropriate category.