A lot of forums have a section for writing.
Fan fictions, scripts, stories, poetry, songs...
I have written and posted probaly about fifteen seperate pieces on a different forum, I'm constantly giving writers feedback on the stories and constructive critisicm... which helps writers improve their skills.
Heres an example...
http://www.gtaforums.com/?showforum=78A lot are Grand Theft Auto fan fics... but there are a lot of origional pieces in there
If you need anybody to write the pinned subjects for the rules and tips I'm happy to do it