It depends on what you mean by “APA.” If you mean straight-from-the-source guidance on requirements of ethical research—from protecting confidentiality to citing sources—go directly to the Publications Manual of the American Psychological Association (6th ed.). For useful discussion on the nuances of APA style, visit the APA style blog at http://blog.apastyle.org/.
For guidance applying APA style to your dissertation, see the Capella’s Dissertation Format Guidelines.