Thermal calculators http://www.novelconceptsinc.com/calculators.htm
Hundreds of CPU heatsink tests in real world conditions http://www.madshrimps.be/?action=getarticle&articID=389
Thermal conductivity http://en.wikipedia.org/wiki/Thermal_conductivity
Properties of metal – Thermal http://www.engineersedge.com/properties_of_metals.htm
Thermal Conductivity of Metals http://www.engineeringtoolbox.com/thermal-conductivity-metals-d_858.html
Heat conduction calculator http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/heatcond.html#c1
Thermal conductivity unit conversion calculator http://www.gordonengland.co.uk/conversion/thermcon.htm