The Modern Language Association takes a fresh look at documenting sources in the eighth edition of the MLA Handbook. Previous editions provided separate instructions for each format. In this new edition, the MLA recommends instead one universal set of guidelines, which writers can apply to any type of source.

Purdue Online Writing Lab (OWL) Guide to MLA

The Chicago Manual is a comprehensive style manual used throughout the U.S. publishing world, perhaps more comprehensive than most college students need, but containing much useful advice on matters of punctuation, capitalization, and word choice as well as on the documentation of sources.

Purdue Online Writing Lab (OWL) Guide to Chicago Style