Sony Reader Daily Edition 4-174-983-12(1) - Manual (Page 101)

101
Reading Books
Deleting a book – “Delete Book”
You can delete the currently viewed book on the
Reader or memory cards that are inserted into the
Reader.

In the book page, press the OPTIONS button,
then tap “Delete Book.”

Tap “Yes.”
The book is deleted and the screen switches to the
book list.
Hint
 You can also delete books from the option menu of the book
list ( page 121 ).