How do you format a bibliography in APA Style?

APA Style calls for a list of references instead of a bibliography.

The requirements of a reference list are that all references cited in the text of a paper must be listed alphabetically by first author's last name in the list of references and that all references listed must be cited within the text.

A bibliography, however, typically includes resources in addition to those cited in the text and may include annotated descriptions of the items listed.

In general, the list of references is double-spaced and listed alphabetically by first author's last name. For each reference, the first line is typed flush with the left margin, and any additional lines are indented as a group a few spaces to the right of the left margin (this is called a hanging indent).

For example:
APA Publications and Communications Board Working Group on Journal Article Reporting Standards. 
      (2009). Reporting standards for research in psychology: Why do we need them? What might 
       they be? American Psychologist, 63, 839–851. doi:10.1037/0003-066X.63.9.839