Footnotes are the preferred citation method for the Chicago/Turabian Notes and Bibliography citation style. When using footnotes, you create what is essentially a "mini-citation" at the bottom of the page. These footnotes guide the reader to the corresponding entry in your bibliography.
Different types of source require different citation information, but they always follow the form of: author, title, publication information, and then either page number or website URL (all separated by commas). And remember, this information will also be contained, in a slightly different form, in your bibliography.
Book by a Single Author
1. Steven Pinker, How the Mind Works (New York: Norton, 1997), 223.
Book by Two to Four Authors
2. Stephen Dubner and Steven Levitt, Freakonomics (New York: William Morrow, 2005), 101.
Book by Five or More Authors
3. Theodore Brown et al., Chemistry: The Central Science (Upper Saddle River: Prentice Hall, 2005), 642.
Journal Article
4. Andrew Byrd, "The Resurgence of the Meerkat," Southern African Ecology 32, no. 1 (2009): 221.
Electronic Journal Article
5. Andrew Byrd, "The Meerkats Have All Gone Away," African Ecology Online 18, no. 2 (2006): 169, accessed October 31, 2015, http://www.afrecoonline.org/byrd1.htm.
Website with Author and Publication Date
6. Cara Nelson, "The Top Three Movies of All Time," Best Movies, last modified June 26, 1993, http://www.bestmovies.com/nelsoncara1.htm.
Website with Unknown Author and Publication Date
7. "Some Cool Movies," Best Movies, accessed October 14, 2015, http://www.bestmovies.com/anonymous.htm.