Off the Record: The Private Papers of Harry S. Truman, edited by Robert H. Ferrell. New York: Penguin. 448 pp. $6.95.

This collection of presidential papers shows Truman's conviction that the republic established by the Constitution was the finest form of government in the history of the world. It also shows his concern for the education of the rising generation for responsible citizenship and leadership. Hence, his decision to establish a library to house his papers and provide information about the presidency which had ''been neglected and misrepresented by so-called historians.'' Author Ferrell writes in a direct, colorful style and includes previously unpublished letters and undelivered speeches.

The private papers are useful as a historical and personal memoir of the Truman adminstration and retirement years.