The Chicago Manual of Style presents two basic documentation systems: (1) notes and bibliography and (2) author-date. Choosing between the two often depends on subject matter and the nature of sources cited, as each system is favored by different groups of scholars.
The notes and bibliography style is preferred by many in the humanities, including those in literature, history, and the arts. This style presents bibliographic information in notes and, often, a bibliography. It accommodates a variety of sources, including esoteric ones less appropriate to the author-date system.
These books and links will help you format government and legal citations. Most other styles will defer to these examples and make reference to the following titles:
The Council of Science Editors - CSE - is the primary authority for biology and other natural sciences formatting style. Scientific Style and Format is the most recognized, authoritative reference for authors, editors, publishers, students, and translators in all areas of science and related fields.
The American Chemical Society is the format and style authority for chemistry. However, each journal may ask for papers to have a different format.
Engineering societies often use the Chicago style but check each association for variations.
The American Mathematics Association has a style for their publications. However check information for authors within the target journal of your interest.
The social sciences usually follow the format of the Publication Manual of the American Psychological Association.