An annotated bibliography is a list of citations to books, articles, and documents and follows the appropriate style format for the discipline, i.e., MLA, APA, Chicago Manual of Style, etc. Each citation is followed by a brief (usually about 150 words) descriptive and evaluative paragraph, the annotation. The purpose of the annotation is to inform the reader of the relevance, accuracy, and quality of the sources cited. Unlike abstracts which are purely descriptive summaries often found at the beginning of scholarly journal articles or in periodical indexes, annotations are descriptive and critical; they expose the author's point of view, clarity and appropriateness of expression, and authority.
See the following resources:
Writing an Annotated Bibliography (from Cornell U. Libraries)
Guide also includes a sample APA annotation
The OWL at Purdue Guide
Overview of how its done and some samples
THE PROCESS
Creating an annotated bibliography calls for the application of a variety of intellectual skills: concise exposition, succinct analysis, and informed library research
o evaluate the authority or background of the author,
o comment on the intended audience,
o compare or contrast this work with another you have cited, or
o explain how this work illuminates your bibliography topic.
The annotation should include most, if not all, of the following:
An annotated bibliography is an original work created by you for a wider audience, usually faculty and colleagues. Copying any of the above elements is plagiarism and intellectual dishonesty.