The study of historical writing -- Merriam-Webster Dictionary
In his classic 1938 paper, historian Carl Becker said, "Now that I am old the most intriguing aspect of history turns out to be neither the study of history nor history itself, in the above noted senses, but rather the study of the history of historical study. The name given to this aspect of history is the unlovely one, as Mr. Barnes says, of Historiography".
Here's a guide written by a history professor at Muskingum College.