Ag Agent Handbook - a collection of background information on crops, pest control, soils, cattle, swine, poultry, agriculture engineering and more.
Agricultural Fact Book 1998 - provides basic facts on U.S. agriculture, including its structure, the farm sector and rural America, as well as an overview of USDA and description of its programs.
Agrinet - developed by the Texas A& M University Agricultural Program, this site provides a single starting point to all agricultural resources on the Internet. It's objective is to promote agribusiness and enhance agricultural product marketing and research.
Census of Agriculture - provides a complete picture of the agricultural sector in the U.S. economy by county, state or zip code.
National Agricultural Library - a major international source for agriculture and related information.
National Agricultural Statistics Service
USDA Economics and Statistics System - has hundreds of reports and data sets about agriculture.
USDA's ERS State Fact Sheets