NASA
The Electromagnetic Spectrum

Electrophysics
How Night Vision Works

Ryerson University
Infrared imaging makes landmine detection more safe, faster

Infrared Processing and Analysis Center & the SIRTF Science Center
Cool Cosmos: Infrared Astronomy Tutorial
Infrared Zoo

How Stuff Works
How Remote Controls Work

The Wide-field Infrared Survey Explorer will map the whole sky in infrared.
http://wise.ssl.berkeley.edu/

Check out this recent BBC story on how “glowing bugs” might become a useful detection tool.