Edging books is a very simple part of stack maintenance. Pull the books close to the edge of the shelf and even out the row. Sometimes the books have been sloppily shelved by a patron, or just moved back from browsing. To ensure that the books are easily accessible to other patrons, it is good to edge them so that the patron can easily see the call number and spine title of the book.
Also look for books that have been pushed behind rows.
When edging, be sure to pull the book from the spine or from farther back on the top of the book. It will cause damage to the book if you quickly pull at the top spine edge of the book. Obviously, we want to keep the books in good condition for as long as possible.