International Traffic in Arms Regulations (ITAR) information
http://www.pmddtc.state.gov/regulations_laws/itar_official.html

Export Administration Regulations (EAR) - United States Dept of Commerce
http://www.access.gpo.gov/bis/index.html

If you're a US supplier exporting your goods, you may wish to refer to this site concerning Shipper's Export Declarations
http://www.census.gov/foreign-trade/www/correct.way.html

Canadian Controlled Goods Directorate (CGD)
http://ssi-iss.tpsgc-pwgsc.gc.ca/dmc-cgd/index-eng.html

North American Free Trade Agreement (NAFTA) information
http://www.cbp.gov/xp/cgov/trade/trade_programs/international_agreements/free_trade/nafta/

Military Standard (MIL-STD) download (requires registration)
http://assist.daps.dla.mil/online/start/

Defence Standard (UK) download
http://www.dstan.mod.uk/

FAR (US Federal Acquisition Regulation) download
http://www.acquisition.gov/comp/far/index.html

NSN (NATO/National Stock Number) search
http://lrc3.monmouth.army.mil/nsn/index.html