"EIA FAQ on CO2 emissions"
I came across these answers to frequently asked questions from the U.S. Energy Information Administration. There’s some good information on emissions and conversion factors:
How much carbon dioxide (CO2) is produced when different fuels are burned? How much CO2 does the United States emit? Is it more than other countries? What are the largest sources of total greenhouse gas emissions by sector for the United States? Where can I find emission factors for greenhouse gases and air pollutants? How much of U.S. greenhouse gas emissions are associated with electricity generation? What are the largest sources of energy-related carbon dioxide emissions by fuel? What are greenhouse gases and how do they affect the climate? Why do carbon dioxide emissions weigh more than the original fuel? Does EIA report water vapor emissions data? How does the hole in the ozone layer affect global warming? How do I convert between short tons and metric tons?