General:

• In Bloomberg hit the yellow CMDTY button (F9).
• For FactSet go to FactSet Insert menu > Quotes/Prices> Futures.
• Global Financial Data features commodity prices back to the 1500s. Login anonymously and click on the GFDatabase. Use the Series drop-down to find Commodity Indices or Commodity Prices.
• UNCTDAD ComTrade has price and flow data dating back to 1960.
• The World Bank Prospects Commodity Markets publishes commodity prices and quarterly forecasts.
• OptionMetrics in WRDS has historical prices of options going back 13 years.
• CRB Commodity Yearbook
  Features historical commodity prices and a brief analysis of various commodities. The Mergent Archive includes .pdf files of the print back to 1939. 

Agricultural:

• USDA National Agricultural Statistics Service gives production, yields and prices for agricultural commodities throughout the world. See also USDA Foreign Agricultural Service PSD Online.
• Consult the Baker Library Research Guide on Agribusiness
• Consult the Guide to Food and Agriculture Organization (FAO) Documents from Harvard College Library.

Metals and Minerals:

• See the Minerals Information from the U.S. Geological Survey.