Carbon footprint Calculators:

http://www.google.co.uk/carbonfootprint// 
http://actonco2.direct.gov.uk/index.html/ 
http://www.carbonfootprint.com/calculator.aspx/ 
http://footprint.wwf.org.uk// Easy to use - reports how many planets it would take to support the human race if everyone had the same carbon footprint as you.

Carbon footprint Information:

http://www.answers.com/topic/carbon-footprint/ 
http://www.mycarbonfootprint.eu/carboncalculator1_en.asp/ Info on what you can save by taking various green actions
http://www.google.co.uk/carbonfootprint/about.html/ Google - link to the Carbon Footprint Project.

Portals for Kids:

http://www.eartheasy.com/article_enviro_sites_kids.htm/ 
http://www.epa.gov/region5/students/projects.htm/ 
http://www.coolkidsforacoolclimate.com/Links/Links.htm/ 
http://www.ecofriendlykids.co.uk// 

General Information:

http://www.morethanwaste.com/Site/Default.aspx/ Information site for waste managers - but contains informative articles for anyone wanting to keep abreast of waste issues.