The Digital Bookshelf will list all digital items that were on you orders and include the order number and title under them.
When you click on the item a side bar will pop up on the right. Most will direct you to open them through your school's LMS (Learning Management System). The school will have links setup for access under the course the item is for.
You can find which LMS your school uses here.
Others once revealed will show Access Codes, sign in information, and links with instructions for accessing the items.