In taking care of antique books, one of the most important initial steps that you should take is to know the parts of the book, so that you can identify the most sensitive parts of the books in order to know how to handle the book. The most sensitive part of antique books is the spine, which takes the most "punishment" when books are opened. It is also the thinnest part of the book. If the book is covered in leather, one of the best ways to keep the spine from breaking is to apply mild leather dressing to keep the leather from becoming brittle and vulnerable to cracking.
Antique books are also very vulnerable to humidity, which can cause the book to stain and fosts the growth of mold. Given this, it would be a good idea to keep the book in a clean and dry area. In addition to this, antique books should also be kept away from ultraviolet light because it can cause the leather cover of the book to fade. If possible, try as much as you can to cover your antique books with stable transparent materials like acetate, which can effectively protect your book from the "elements." Lastly and more importantly, if the cover of your antique book comes off, you should always ask the help of a professional in repairing the book because if you try to do it yourself, you can cause more damage and can diminish the value of the book.