HSV vs. RGB Color: Hue Saturation Value is easier when trying to describe and tweak shades.
Illuminates by Default: whether it starts out linked to everything in your scene or nothing.
Decay Rate: how much the light intensity decreases over time; quadratic is the most realistic.
Cone Angle: size of your light.
Penumbra: the amount of feathering/softness on the edge of your light.
Dropoff: smoothes out differences in light intensity for your eye (reduces mach banding).
Resolution: determines the detail of the map. Use a power of two and start at 1024 and work your
way up as needed to avoid aliasing (jaggedy edges around your shadows).
Filter Size: blurs the shadow edges. A good choice is around 8.
You may face a nasty artifact called shadow banding which creates visible lines in your shadows. You can alleviate this through increasing your resolution and filter size.
* Note: changes to your shadows don’t update in IPR rendering.
Naming will become crucial when your scenes become more complex; start good habits now! I recommend saying what object it is linked to and whether it is a key, fill, or rim. Later you may even want to differentiate by color or whether it has a shadow.
Hiding lights (ctrl+h) in the outliner effectively turns them off while unhiding (shift+h) turns them back on.
Save often and save in iterations! There is nothing more skilled at crashing Maya than rendering.