Begin your citation so that the first line of your citation starts flush with the left margin. It should not be indented at all.
Indent the second and subsequent lines of your citation one half-inch from the left margin if you are using APA style. When you begin your next citation, the first line should again begin flush with the left margin, and subsequent lines should be indented one half-inch.
Indent the second and subsequent lines of your citation five spaces from the left margin if you are using MLA style. When you begin your next citation, the first line should again begin flush with the left margin, and subsequent lines should be indented five spaces.