The links below from Purdue's Online Writing Lab (OWL) have some good information on using ASA style.
A guide from Trinity University has useful examples of ASA 4th edition style
The ASA Style Manual is published by the American Sociological Association. It is designed to serve as the authoritative reference for writing, submitting, editing, and copyediting manuscripts for ASA journals and other publications following ASA's unique format.. When citing sources for a paper, follow your instructor's preferences.
For more information, see the ASA website.
The definitive authority for ASA style is only available in print:
ASA Style Guide, Fourth Edition.
There are two copies available, one on reserve and one in the reference collection. Both are under the call number HM569 .A54 2010