CREEPYPASTA is quite popular with the middle school/high school crowd--my kiddos included. Basically, you can submit your paranormal and short horror stories to be published on the site. There is a submission period (currently open until August 20th) and no guarantee your story will be accepted. Nor do you get paid. But with writing prompts, discussions, feedback, ratings, and a section titled "CRAPPYPASTA" (a collection of shorts "where the author has (given) their express permission to publish...if deemed not quite right for the main creepypasta archive") the site is a perfect venue for the budding horror author.
Please check it out if you have the time!