Each level within an excavation trench represents a particular period in the history of a site. As archaeologists dig, they produce plans like this one of a level of a trench at Jarmo. While it was produced for publication, this plan is similar in style to the preliminary sketches that are often drafted by excavators in the field.
The Mystery of Archaeology
Dr. Gil Stein, Director of the Oriental Institute, talks about archaeology in this video.
Leacroft, Helen and Richard. The Buildings of Ancient Mesopotamia. Reading, MA: Addison-Wesley Publishing Company, Inc., 1974.
Renfrew, Colin and Paul Bahn. Archaeology: Theory, Methods, and Practice. New York: Thames and Hudson, 1991.
Scarre, Chris. Smithsonian Timelines of the Ancient World. London: Dorling Kindersley, 1993.