An annotation may include some or all of these parts:
Gurko, Leo. Ernest Hemingway and the Pursuit of Heroism. New York: Crowell, 1968. Print.
This book is part of a series called Twentieth Century American Writers. After fifty pages of straight biography, Gurko discusses Hemingway's writing, novel by novel. There is an index and a short bibliography, but no notes. The biographical part is clear and easy to read, but it sounds too much like a summary.
Original example from Writing Center at UNC- Chapel Hill.
Waite, L. J., Goldschneider, F. K., & Witsberger, C. (1986). Nonfamily living and the erosion of traditional family orientations among young adults. American Sociological Review, 51 (4), 541-554.
The authors, researchers at the Rand Corporation and Brown University, use data from the National Longitudinal Surveys of Young Women and Young Men to test their hypothesis that nonfamily living by young adults alters their attitudes, values, plans, and expectations, moving them away from their belief in traditional sex roles. They find their hypothesis strongly supported in young females, while the effects were fewer in studies of young males. Increasing the time away from parents before marrying increased individualism, self-sufficiency, and changes in attitudes about families. In contrast, an earlier study by Williams cited below shows no significant gender differences in sex role attitudes as a result of nonfamily living.
Original example from Cornell University Library.
Below are the most common types of annotated bibliographies: