Children's biographies are of two writing styles: authentic biographies, which are carefully researched, and fictionalized biographies that make use of a story approach rather than straight reporting. Autobiographies are written in the same two styles. Some stories are complete fiction and simply make use of a real person around whom to base the plot.

Trends in biographies include an emphasis on authenticity and an increase in the number of titles about African Americans, women and ethnic minorities. Many biographies are written about popular culture celebrities, often in series books that are written to fit certain format specifications. In recent years, biographies have received several prestigious awards.

Criteria for children's biographies include a fast-moving narrative, a choice of subject that offers to enrich children's knowledge, accurate information, authenticated sources, balanced portrayals, documented quotations, believable invented dialogue, appropriate choice of the point of view, research materials smoothly integrated into the narrative, presentation of the character as multidimensional and believable, and a fair and balanced interpretation.

Biographies are written in several forms: picture-book biographies, simplified biographies with easy-to-read text, partial biographies which include only a portion of the person's life, complete biographies, collective biographies which focus on several persons with similar role relationships, autobiographies, and memoirs.