Consider getting authorization to write your biography. If your subject is deceased, getting authorization from his or her estate prior to writing the biography will aid in your research efforts. Obtaining authorization may allow you to interview the sources closest to your subject, such as family members and lovers. You may also be able to gain access to your subject's journals and diaries, which will give your readers an intimate look into their life.
Research your subject. Once you have chosen a memorable person to write about, try to get "inside" their life by contacting family members and friends for interviews. If you haven't been able to obtain authorization from a deceased subject's estate, gather intimate information via radio and television interviews, previous biographies, and conversations with their coworkers and neighbors, if possible.
Visit places of importance to your subject. If you are able to, plan a trip to your subject's place of birth, hometown, or any other location that set the stage for a major life moment. While you are at these places, gather background information about the locations to research how they contributed to your subject's life experiences. Speak with locals to learn "inside" information about your subject, and how he or she impacted the lives of people around them.
Conduct interviews with important people in your subject's life. One of the keys to writing a compelling biography is to provide "secrets" about your subject's life, details that the general public would have no way of knowing without reading a biography. One of the only ways to get this confidential information is by conducting interviews with the key players in your subject's life. Make a list of questions and email them to your interviewee - you can also arrange an in-person or phone interview.
Write the biography. After you have collected all of your information, it is time to start composing your book. Be sure to include all of the major events in your subject's life, as well as major and minor accomplishments. Speak about how the time period in which your subject lived in may have impacted their life story, and make sure you thoroughly explain how this person impacted society.