This tutorial covers drawing a simple room in one-point perspective.
Learn how to create depth using linear, or mathematical, perspective!

In this video, I am using a Prismacolor Ebony drafting pencil, but you can use any kind of pencil - plain old HB pencils work great! Try to stay within the HB-2B range for general sketching. Too hard of a graphite (the higher the H, the harder the graphite) is really light and can indent the paper easily if you press too hard. The higher the B, the softer the graphite, which will create darker marks!