Biography's Most Popular Categories
The categories in the biography genre can be all-encompassing or quite narrow, targeting a small but receptive market. For example, in the limited category of local politicos, a biography about a popular mayor of a small city in Oklahoma would sell well among the city's citizens, so it's not unlikely a publisher could be secured. But for the most part, biographies are written about well-known people who are the subjects of the larger categories.
The subject of a biography need not be human. For example, the bestseller Dewey: The Small-Town Library Cat Who Touched the World is written by librarian Vicki Myron, who found Dewey stuffed into the library's book slot on the coldest night of the year. The book recounts the cat's nineteen-year life that inspired people all over the world.
Life Stories about Celebrities
People are interested in the lives of celebrities, as can be seen from all the magazines and tabloids covering these icons and the 4,000-plus biographies written about them that are readily available. Indeed, a number of biographies are marketed, if not actually written, with the salacious in mind. For example, in writing the summary for Doris Day: The Untold Story of the Girl Next Door by David Kaufman, the publisher describes the book as “scintillating tales of fame, beauty, money, tragedy, sexual ambiguity, and sexual conquests.”
Frequently, these books are authored by the celebrity/subject himself with the help of a ghostwriter. Sometimes the celebrity writes of his own life experience with another person who is technically the subject of the book, thus making it more of a biography than a memoir. A recent example is the bestseller Big Russ and Me, in which Tim Russert writes of his life with his father. More common however, it's another person who writes the biography.
Historical Biographies
With more than 10,000 titles in print, historical biography is one of the largest categories in the genre. Some historical periods provide more fertile grounds than others for finding subjects, such as the years leading up to the founding of the United States and the early decades of the nation during which figures like Franklin, Washington, Jefferson, Adams, and Hamilton lived, of whom hundreds of biographies have been written.
The timeliness of your subject can be a factor in choosing whom you want to write about. For example, The Snowball: Warren Buffet and the Business of Life by Alice Schroeder became a bestseller when the financial markets were in turmoil and people sought guidance and inspiration from the life of this successful financier.
If you decide to write about a person of whom a number of biographies have been written, you should try to concentrate on a unique aspect of the person's life or write about the subject from a different perspective, perhaps focusing on a different time period in that person's life. Alison Weir has done this repeatedly with her subjects, including Henry VIII, Eleanor of Aquitaine, and Britain's royal families.
Scholars and Specialists
Along with books about scientists and inventors, biographies about scholars and specialists are often written by experts in the subject, unlike other books in the genre, where being an acknowledged authority is not required. For example, Pascal's Wager: The Man Who Played Dice with God was written by James A. Connor, who holds a PhD in literature and science.
However, do not be dissuaded from writing a biography about a scientist or scholar if that is your desire. Many of the biographies that have been written about Albert Einstein are by authors who were neither scholars nor scientists. It is also possible that a nonexpert is better suited for a particular biography, depending on the approach and perspective of the project. For instance, a book on the life of Alan Turing, the English mathematician who cracked the Enigma codes of World War II and whose career ended after his arrest for violating antihomosexual laws, needed an author who could convey the suspense of breaking the code and the drama of the criminal charges. Hence, David Leavitt, neither scholar nor mathematician but rather an author of novels and short stories, proved perfectly suited for the project.
Politicos and Sports Figures
Books about politicians abound and with 10,000 titles, it is one of the largest groups of biographies. In addition to the regular standbys that are timeless — Lincoln, Theodore and Franklin Roosevelt, Benjamin Franklin, and John and Robert Kennedy — contemporary politicos are always ripe for a biography.
It is not unusual for active politicians to pen their own memoir/ biography usually with a ghostwriter, and this is also the case for celebrated sports figures such as the renowned basketball coach John Wooden who, with Steve Jamison, wrote Wooden: A Lifetime of Observations and Reflections On and Off the Court. Typically however, biographies about sports figures are written by someone other than the subject and generally the book needs to go beyond playing the game. In The Express: The Ernie Davis Story by Robert Gallagher, the biography of the scholar/athlete is set against the backdrop of the civil rights era in which he lived.

