Stage lighting, in it's most basic form, is what allows performers to be seen clearly onstage.
Where does stage lighting come from?
Stage lighting is either free standing or hung. Lighting that is hung will usually be in front of the stage, and lighting supported on stands will usually be at the back of the auditorium.
How many lights do you need?
This is a complicated question to answer. It depends on the size of your stage and the type of performance. It is also important to realize that the fewer lights you have, the more pronounced the shadows will be (and shadows, in general, are undesireable). A very basic number would be eight - four coming from each side of the stage. See the sample lighting system below.
Can't I just use the overhead or "working" lights?
Um, no. The first problem is that light coming directly down from the ceiling will light your actors heads, not their faces. Second, these lights are meant to light up the whole stage and will therefore leave absolutely nothing to the imagination (including what is happening backstage. Third, these lights are usually flourescent and make everyone look awful.
What do you recommend for a beginner?
If you need a portable system, or want the cheapest solution, or don't want to mess around with "hanging" lights, lighting on stands is probably your best solution (see the pic below). Buying a lighting package is by far your easiest bet because it comes with everything you need, they are easy to set up, and you get a much better price than if you bought pieces individually. The following package is a good example of what you should be looking for:
