Books, especially diaries, are often already weak in their structure from lots of handling. They need to be treated gently if they are to survive.
Wearing cotton gloves can help protect a book's binding, particularly if it is a fine leather binding that may be stained by body oils.
Do not use leather dressings on leather bindings. If you are worried that a leather binding might crack, seek professional advice.
The only cleaning that a book needs is regular dusting, particularly of the top edge, or 'head' of the book.
The dust jackets of valuable books are themselves valuable. Store them safely away and make a replacement dust jacket for the book out of acid-free paper.
Be wary of putting place markers or bookmarks into book pages. One or two to help quickly locate a frequently used reference may be fine, but too many can cause strain on the spine, causing it to split open.
When putting books on a shelf, do not wedge them tightly. On the other hand, use bookends to stop books from slumping or falling over if there is an insufficient number of them to fill a shelf.
When removing a book from a shelf, do not pull it out by the top lip of the spine. This will eventually result in the upper spine tearing. There should be sufficient space in a row of books to be able to insert your fingers each side of the covers to grip the book firmly enough to remove it.
Some books are best stored flat on shelves. These include large books with limp covers, very wide books, books with loose covers or those where the body is falling apart. Books that are coming apart should be wrapped in acid-free tissue and put in a storage box to prevent further damage.
Large or fragile books should not be stacked one on top of each other.