When you click on an item from the Reserve Items page you are brought to a page that tracks the history of that item. From this page (seen below) you can choose to view the item (which will bring you to the PDF of or webpage for the reading) or edit the item. (You may also delete the item entirely by selecting the "Delete item" button at the bottom of the page.)
From the "Edit Item" page you will be brought back to the original form that was filled out to add the item (seen here). From this page you can add or edit tags or change information about the title, if required.