One of the basics in art that many people have a hard time with is perspective. Mostly from what I know and see people over-think it.
In art, perspective is
a technique of depicting volumes and spatial relationships on a flat surface,
according to dictionary.reference.com.
Basically, put what you see on the piece of paper.
Many get all worked up about that they can't get it to look right, even I'm guilty of this, but relax. You're taking a 3 dimensional world and putting it in a 2 dimensional world, some things are going to get a little wonky. Though perspective is a giant subject so don't expect to just get it overnight either, unless you're some artistic genius. I'll come back to perspective several times in later posts but for now I'll just take a little dip into this giant pool.
I'll start with the basic one point and two point perspectives. These show how the objects will relate to each other based on lines in certain directions to the horizon.
Horizon: the line across dividing the paper into 2 sections. Think of like the horizon between the sky and the ground.
Center of vision: the imaginary line where the center of your vision (view) is, the center of the drawing.
Vanishing Point: the point at which lines converge or where all the lines go.
Eye level: the horizontal line where your vision, this is kind of like the horizon line but this doesn't have to be the horizon line
Here are some perspective drawings I've done of two different hallways: