Annotated bibliographies are descriptive and evaluative lists of resources. They may include citations to books, journal/magazine articles, web sites, or other materials. Annotated bibliographies start with a citation which is followed by a brief paragraph (the annotation, normally around 150 words) that describes and also evaluated the information.
Annotations are different than abstracts! Abstracts are only descriptive summaries of resources. Annotations are descriptive as well as critical; they look at the point of view of the author, clarity, authority, and usefulness of the source.