Articles:
http://support.esri.com/en/knowledgebase/techarticles/detail/37264
http://blogs.esri.com/esri/arcgis/2012/01/20/sun-glints-add-realism-to-your-map/
Manuals:
http://docs.qgis.org/html/nl/docs/user_manual/index.html
Publications:
http://downloads2.esri.com/edcomm2007/bok/GISandT_Body_of_knowledge.pdf
Training:
http://training.esri.com/gateway/index.cfm
http://training.fema.gov/EMIWeb/IS/is922.asp
http://wiki.python.org/moin/BeginnersGuide/NonProgrammers
http://open.ems.psu.edu/courseware
http://www.osgeo.org/educational_content
http://www.codecademy.com/#!/exercises/0
http://freecomputerbooks.com/specialGISBooks.html
Tutorials:
http://video.esri.com/watch/663/getting-started-with-modelbuilder
http://www.nws.noaa.gov/ndfd/gis/ndfd_GIS_tutorial.html#download