The American Psychological Association website sells a published manual containing the most comprehensive APA style guidelines. As of 2015, prices range from $29.95 to $39.95 for soft-cover, spiral-bound and hard-cover editions. The APA also publishes a concise guide for $29.95.
The APA website provides free access to a PDF tutorial outlining some of the most relevant style guidelines, such as manuscript and citation formats. The tutorial also includes links to examples of sections frequently used in research papers, including a sample abstract. The Purdue University Online Writing Lab and the Cornell University Library websites also post free APA style resources for formatting and citations.