Determine what questions the biographical sketch should answer. Find out what the target audience wishes to know about the person, what important events shaped the person, and what impact the person had on others. The slant of the biographical sketch will vary depending on the target audience. A biographical sketch of a famous poet might focus more on influences and important life events, whereas a biographical sketch for your business website should detail how your experience and credentials can help customers. Write the questions about the person down on a sheet of paper or in a word processing document.
Research the person to answer the questions you wrote down. Use a variety of sources, if possible, including biographical material from other biographers, accounts from friends and family, as well as primary sources. Cross-reference facts across multiple sources for accuracy. If you come upon any relevant discrepancies or contradictions, make a note of them so you can later include in the biographical sketch that there are differing opinions on that particular point.
Research the time period and country the person lived in to provide a context to his actions and life. For example, a writer's work may have been influenced by the Vietnam War or the Beat generation. Keep reference materials close at hand, such as history books, maps, or time lines, to provide quick references.
Organize the information after researching. Use only the information that your target audience will find important, and discard unimportant or irrelevant information. Use the questions you wrote down to help decide which information to keep and what to discard. Use basic biographical information such as birth date, place of birth, and time of death to provide a framework for the biographical sketch. If you're writing a historical biographical sketch, avoid omitting information just because it is controversial or distasteful--you want to provide an interesting but complete and accurate picture of the person's life without removing large chunks which may provide misinformation to readers.
Start the biographical sketch by writing a story or anecdote. Writing an interesting story or anecdote about the person in the opening paragraph of a biographical sketch helps hold the reader's interest and makes it more likely the reader will read the rest of the biography. The story or anecdote should be relevant to the information presented in the biography, and help highlight or give a framework to the subsequent information. For example, a biographical sketch about Newton might first start with a story about how an apple falling on his head gave him the inspiration for discovering the law of gravity.
Write the rest of the biographical sketch. The body of the biographical sketch should detail the most important facts of person's life in chronological order and answer the questions you wrote down about the person. The biographical sketch should be short, at least three paragraphs but no more than two or three pages. Write in the third person, even if you are writing about yourself, and present facts from an objective standpoint. At the same time, keep the biographical sketch interesting and fresh so that readers remain interested and read until the end.
Put the biographical sketch away for a while, ideally a few days or a week, and then look at it later to make revisions. Fix any grammatical errors, such as misspellings or run on sentences. Tighten any wordy sentences to make them more concise, and review the information you presented to see if anything can be deleted without effecting the overall picture of the biographical sketch. If possible, have someone else review the biographical sketch to make any further suggestions for improvement.