Jessica Gill, writing in the Newburyport Current (MA), discusses what is involved in donating one’s original personal papers (or those of your family members) to local organizations that can help preserve them and make them available to others doing genealogy research. The Newburyport Archival Center is but one example of such an organization (and a good one at that).
From the article:
The Newburyport Archival Center at the Newburyport Public Library would love to provide a home for these materials. We have a great respect for their intellectual value and are ready, willing, and able to care for them in order to ensure their protection for future generations. Not only this, but we delight in making this material available to researchers who visit our archives.
One other thing – if you happen to publish a book about your family’s history, and you have left out details of those still living, it might be a good idea to make a few copies available to your local library and any other organizations that would be interested in this. That way copies are preserved and available even if you’re not.