http://www.oneworld.org/energy/whatis.html Great site answering the question: What is energy?
http://jersey.uoregon.edu/vlab/ University of Oregon Physics department site -- lots of good information on laws of thermodynamics with applets that illustrate the explanations.
http://www.secondlaw.com/two.html#time A wonderfully readable chat about the laws of thermodynamics, definitely way beyond what is needed for the unit but helpful for general understanding.
http://my.unidata.ucar.edu/content/staff/blynds/tmp.html This is a great place to learn about the meaning of heat!
http://auto.howstuffworks.com/inside-engines-roundup.htm Use this site either as a teacher resource or to use in a whole class discussion -- especially if the interactive engines can be shown to the class.
http://www.epa.gov. Good information on global warming, and a plethora of general environmental information.
http://www.epa.gov/teachers. Great curriculum information, grant suggestions, workshop and conference info.
http://science.howstuffworks.com Great source for information on greenhouse effect.
http://climatechange.unep.net/. Information on federal Fossil Energy Programs
http://www.energy.gov/engine/content.do?. Science Education Initiative of the Department of Energy
http://www.worldwatch.org/ A leading source of information on the interactions among key environmental, social, and economic trends.
http://www.ct.gov. Statewide information on environmental quality and pollution prevention
http://www.dep.state.ct.us. Good source for auto emission information
www.noaa.gov. Good source for global warming stuff
www.ncdc.noaa.gov National Climatic Data Center. Great information on weather and climate
www.epa.gov A complete global warming website
www.csde.state.ct.us The Connecticut State Department of Education website. This is the place to go for CAPT related materials.