NASA
Nasa: Mission: Science: Electromagnetic Spectrum: Infrared Waves
Infrared light lies between the visible and microwave portions of the electromagnetic spectrum. Infrared light has a range of wavelengths, just like visible light has wavelengths that range from red light to violet.
University of California
Center for Science Education: Gallery
A gallery of astronomy images which depict galaxies, comets, the moon, planets, nebulae, supernovae as seen in various regions of the electromagnetic spectrum. Each image in the gallery is described. Fascinating!