I've focused on the southeast and midwest in this lunchtime series because I'm interested in what's going on in my own neck of the woods.  If you want to learn more about your part of the country, you might like to check out some of the texts I used in my research.  Here's an annotated bibliography to get you started.

Doolittle, W.E.  2002.  Cultivated Landscapes of Native North America.  Oxford University Press.

Heilman, J.M., M.C. Lileas, and C.A. Turnbow.  1988.  A History of 17 Years of Excavation and Reconstruction --- A Chronicle of 12th Century Human Values and the Built Environment.  Volume 1.  The Dayton Museum of Natural History, Dayton, OH.

Lentz, D.L.  2000.  Imperfect Balance: Landscape Transformations in the Precolumbian Americas.  Columbia University Press.

Scarry, C.M.  1993.  Foraging and Farming in the Eastern Woodlands.  University Press of Florida.

And, of course, if you're completely new to the topic and want to learn a bit more about what North and South America looked like before European contact, I highly recommend the mainstream books 1491, Indian Givers, and Guns, Germs, and Steel.  What books do you think should go on the reading list of those interested in Native American agriculture?