The basic APA format for a print book is:
Author, Initial. Initial. (Year).
Title. Publisher.
Watters, E. (2010). Crazy like us:
The globalization of the
American psyche. Free Press.
For e-books, follow a similar pattern, but list information about where you accessed the book instead of publication information:
Fromm, G. F. (Ed.). (2011). Lost in transmission:
Studies of trauma across generations. Retrieved
from http://0-site.ebrary.com.libcat.uafs.edu