How do I create a new form of light? I’m interested in creating some architecturally useful lights which are well calibrated.
do you mean adding new lights?
press spacebar in the 3D window - add - lamp - then choose the light you want (spot, lamp, hemi, sun)
you can change the settings for each light you add
here is a list of tutorials
http://wiki.blender.org/index.php/Tutorials/Links#Lighting.2C_Shadows_and_Rendering