Sites: 

National government /International Standing
Climate Change Research and Modeling Centers
NASA
Top world climate center. Vital Signs of the planet - most user friendly platform.Online tool for past and present temperature maps. Section for kids
UK Met Office
Hadley center: Top world climate center. Basics in short videos.
Videos by experts on key topics
Has Google Earth for temperature projections. 
Canada Climate Models
Projection maps & animations
University Corporation for Atmospheric Research
The best site on coverage of all the aspects. Understanding Climate Change Global Warming Excellent primer page. The UCAR climate change model is a world leader and the animations on global warming projections are the best..
MIT Centre for Global Climate Change Science
Global Integrated Climate Model is the most advanced.
On business as usual global emissions the model projects a global average temperature increase of 7.2C by 2100  The results are on line. A climate scientist site.
Caution on climate models that the science relies on.
The IPCC cautions models are only projections and not to be used for prediction - but they are. ) 
Max-Plank Institute Metereology
Advanced model research.Site for scientists. Short climate by FAQs page.

Commonwealth Scientific & Industrial Research Organization Australia. Important global carbon modeling research. Understanding Climate Change page.
Climate Change E-book
NCAR
Focus is mainly on research, but offers this page with educational resources
NASA Earth Observatory
Superb -see in Global Maps, Features, Fact sheets
Most of these centers have public education sections which we link to on this site.
Those that don't are at the end of this list. 
NOAA climate portal. Regular global temperature and precipitation changes. State of US climate. Annual state of global climate. 
UNESCO excellent resource- the top determinant of sustainability is now global climate change