Vicki gave some really good info.  I would also read some melodramas as well.  I would also get the book Between the Hisses from Pioneer Drama.  It gives a good history of Melodrama, as well as classic poses, music to use and a description of olios.  I would also read some melodrama scripts.  1800's melodrama were serious plays and you can see that in such scripts as "The Drunkard".  Modern melodrama is a bit more light hearted and scripts written by Tim Kelly are good ones to read.  One thing about meldorama to remember is that good and evil are very black and white.  Good always wins through virtue and evil is always punnished.  There is also always a villain, a hero and a heroine.  There is almost always theme music and the audinece participates by Booing the villain, Cheering the Hero, and Awwwing for the heroine.  Modern melodrama is very stylized.  While it is over the top and exaggerated, the actors MUST play their parts straight other wise it isn't going to fly.  I hope this helps.  If you need anything else let me know.