Some places to send your short story. If there's no editor's name, just write "Dear Editor:" in your letter's salutation.
Teen Ink
P. O. Box 30
Newton, MA 02461
Chris Rice, Director
Young Authors 2010
Fiction Writing Department
Columbia College Chicago
600 S. Michigan Avenue
Chicago, IL 60605
Merlyn's Pen Magazine (online)
Various other contests
(see me for details)