You can use My Account to see a list of books which you have borrowed. This can be useful when you are writing a bibliography, however the list will not include journal articles or electronic books. To see the list click on Reading History. To delete a book from this list select the item and click on Delete Marked, to delete all items click on Delete All. It is possible to opt out of the reading history service at this point too.
Please note that once an item has been deleted this action can not be reversed.