When a competition is announced in this forum, you will need to post a reply to the topic saying if you're going to join. Your name will be added to the list of people participating in that contest. When enough people have joined the contest the person running it will post a topic in the Entries forum where you can post your entries. If you are entering a story-writing contest, please post a new topic in the Entries forum when directed by the person running the contest, stating in the topic title what contest you're participating in and the date of the contest.
When the competition has been running for the amount of time stated in the original post, the entries topics will be locked and a poll will be posted in the Voting Forum, where other members of the forum will vote for the one they consider to be the best. After a week, the voting topic will be locked and the winners will be announced in the Results forum.