The library community will probably ban me from all future
    endeavors, but...
    Organized your collection to mirror your interests.
    I have organized several private library collections (church,
    art, personal, ship board) and each time I have catered to the
    client.
    1. If you have more than 5-10 books on a subject, assuming
    you have a very small library, make them into a category. Also
    arrange a vertical file cabinet with the same categories. This
    works for natural history (each animal or group of animals, etc)
    as well as history (region, city, family, time era) and any other
    category you may have. Keep in mind the exhibits and artifacts
    you have as well. The library should serve to compliment, explain,
    and enhance them. Therefore your categories should compliment
    each other.
    2. Make ample cross references. If you decide, for example, to
    make your categories by geographic region, make sure you have
    many cross references as to time frame or people's names.
    3. Keep a card file or a spreadsheet information document for
    each book, pamphlet or other item worth saving. It should have
    any provenance (if donated, or of special value) as well as the
    normal library bibliographic information. A local library should
    help you there. There are several small library software programs
    around that may be perfect for you.
    4. A your collection grows, you may find that using an adaption
    of Dewey Decimal may work, but remain flexible.
    5. Good luck
    Nancy Wynen
    Florida Atlantic University
    Boca Raton, FL