How do you cite a book with more than one author?

You site it as you would regually and just add Volume 1 or whatever it is after the book.

Here are examples using a fictional author and book title.

Smith, Gerald. Little Known Facts about Tigers, Vol. 1, p. 24. City, State (if city is not well known): Publisher's Full Name, Year.

For Editors, rather than authors:

Terleka, Mildred, Johnson, Michael, Eds. New Philadelphia, Ohio Historic Homes and Buildings, Vol. XI, pp. 34-98. Chicago: Right Publishing House, 2009.

Make sure you are using the correct style for citations, example MLA, or APA, etc.