When i first started here I had no idea how to submit articles to publications either. I couldn't find instructions how to do that so had to ask around. If you have applied to join a publication as a writer (which you normally do through a comment on the Publications welcome or submission guideline post) and are accepted, after you write an article, don't hit publish, select the dropdown screen just to the right of the publish button, and choose "submit to publication" and choose from a list of those you write for. Then it will be placed under consideration by the editors, and you will be notified when accepted. If it isn't approved they will usually leave you a private note with reasons why and things to change. I hope that helps.