Excellent free online course on visualisation

Excellent resource:
"Visual Literacy: An E-Learning Tutorial on Visualization for
Communication, Engineering and Business"
http://www.visual-literacy.org/

see in particular:
http://www.visual-literacy.org/periodic_table/periodic_table.html and for
tools
http://www.visual-literacy.org/pages/maps/mapping_tools_radar/radar.html

Best regards,
Christian