Stories go under the "Literature' Section in the proper sub category
Once decided where it belong open the sub category and on the right hand side at the top will be a line with "New Topic" - press it and you'll be taken to a submission board where toy can either copy text into the box or write it. Once done you can 'preview' the way the story will appear on the site, allowing you to go back into the box and make any spelling corrections, punctuation corrections , respacing into paragraphs (Nothing will earn you a bad review faster than the dreaded "wall of words")
Once pleased with things just click on the post button and on the main screen of the sub category your story will appear at the top until replaced with a new piece!
Hopes that helps!