An annotated bibliography is basically an enhanced Reference List. It contains an alphabetical list of References, with each one followed by a descriptive or critical annotation. Longer annotated bibliographies can be divided into different sections. Format an annotated bibliography the same way you would a reference list:
See the Perdue OWL for an Annotated Bibliography Sample in MLA format.
An annotation is a brief paragraph (100-200 words, usually) describing and/or critiquing a resource. Annotations may address some or all of the following points:
One of the purposes of an annotated bibliography is to aid you in your research. By keeping notes related to the resources you look at, you will be able to refer to them later and know which ones would be most suitable to look into at a later date. With that in mind, you may also want to include in each annotation a brief description of how the resource in question is helpful to YOU specifically. Note what features, ideas and/or perspectives it will be contributing to your particular research.