You can add pictures, videos and documents to individual list items by first uploading them to the Information Library.
Go to the article Adding Media to the Information Library to learn more.
Once you have your media uploaded to the Information Library you can now attach it to Lists. To access this go to Content then Lists either create a New List or update an existing one.
Open the List Item and then under Search and Attach Information type in the Category, Subcategory, or File name. In the dropdown it will categorize it in that order.
On the iPad you will see once the list is open an "i" this shows that there is something attached to the item and your employees can click it and access this file when they are completing the list.