The site at: http://209.41.43.90/kade/shock.htm is an interactive mini-lighting lab where you can control the lights on a scene. Open this site and see what it feels like to be the lighting designer for a production.
This remarkable site is maintained by the United State Institute of Theatre Technology (USITT) and is an index of articles, web sites and scenic and costume designs that have been submitted. It is treasure trove of theatre design images. Visit this site and see if you can find some costume and scenic designs for some of the plays mentioned in Theatre. Does seeing the design improve your vision of the lay? Were the designs what you envisioned when you first read the play?