Add a Basic Light
Maya 2012 Tutorial
How to Add Light in Maya
By default, Maya includes a light in every new scene. As soon as you add a light, the default light turns off and your new one provides the scene's illumination. You can add several lights to a scene and the shadows can be enabled for specific lights. Don't feel it is necessary to enable shadows for all of the lights.
Choose Create > Lights > Spot Light (include options). This is the simplest type of light Maya offers. A spot light illuminates in only one direction.
In the options box, choose the light color by clicking the color rectangle. Specify whether or not you want shadows by selecting the Cast Shadows checkbox.
Click the Create button and a light is added to your scene.
Select the light and press the "t" key. A manipulator appears. Using the Move tool, move the light and manipulator individually to set the light's location and look-at point.
The lights settings can be adjusted by selecting the light and opening the Attribute Editor.
To soften the light's edge, adjust the Dropoff and Penumbra Angle sliders. Decay Rate controls the light fall-off rate. Objects further from the light source will receive less illumination. To simulate the way lights work in the real world, set the Decay Rate to Quadratic.
Resetting Light Settings
Whenever you create a light, a new light object is created based on the last time a light was added. To reset the new light to the default values, open it's options and choose Edit > Reset Settings.