Agricultural Economic Organizations:

Agricultural & Applied Economics Association

AAEA - Extension Section

AAEA - Committee on Women in Agricultural Econoomics

Southern Agricultural Economics Association

Western Agricultural Economics Association

Association of Environmental and Resource Economists

Graduate Student Section (GSS) and Graduate Student Organization (GSO) University Chapters

Research Links:

AgEcon Search: Research in Agricultural & Applied Economics

USDA/ERS Data

Interesting Links: 

Departments of Agricultural Economics

United States Department of Agriculture

News:

The Wall Street Journal

CNN Interactive

MSNBC News

The Economist