The citations (bibliographic information - title, date, author, publisher, etc.) in the annotated bibliography are formatted using the particular style manual (APA, MLA, Chicago, etc.) that your discipline requires.
Annotations are written in paragraph form, usually 3-7 sentences (or 80-200 words). Depending on your assignment your annotations will generally include the following:
A descriptive annotation (citation in APA format):
Carson, R. (1962). The obligation to endure. In Silent spring (pp. 5-13). Boston: Houghton Mifflin.
Carson talks about the overuse of chemicals to kill insects and other pests that invade and harm the nation's environment and agriculture. She thinks that chemicals that people once thought would control disease in plants are now going to cause another worse kind of disease in humans. She uses some history and current realities to back up her points.
An evaluative annotation (again, APA format):
Carson, R. (1962). The obligation to endure. In Silent spring (pp. 5-13). Boston: Houghton Mifflin.
Carson, in this chapter from Silent Spring, claims that chemical pollution, especially in the form of pesticides, is "the most alarming of all man's assaults upon the environment" (152). Modern science's creation of new chemicals (almost five hundred a day) and their subsequent use--two hundred of them alone used to kill pests of all kinds--have begun to alter the biological environment irrevocably, so that nuclear warfare is no longer the most certain means of wiping out life on the planet. Instead, the real killer becomes the many poisons we use to wipe out pests. These already are causing and will cause ultimately all kinds of genetic alterations in plant and animal life that will bring about the end of life as we know it. Carson does not advocate a complete end to chemical pest control, but she does insist that chemicals should be used only after they have been thoroughly investigated, tested, and understood. And then they should be used only by those who understand how to use them and their potential for both benefit and harm.
The second annotation is longer than the first, but it is also evaluative. A descriptive annotation is simply a list of topics an author talks about, while an evaluative annotation states conclusively what the author thought about, how he/she thought about it, and what it finally meant for the piece of writing he/she produced. Ask your instructor how you should write your annotations.