Where do I put an article for it to be published?

You will always create your articles somewhere in your member folder.  When you create an article (or a news item, a blog, or anything else) its state will be private.   The state of an object on the site governs who can see it.  A private object can only be seen by the owner (you) and the site management.  You can change the state of your article by using the state tab attached to the top of your article. Other states are public draft (visible), pending, and published.  To change your article to public draft, simply select make visible from the state tab menu.  Public draft articles can be seen by everyone, but they are not yet indexed by the site.  This means that they don't appear in the Articles button in the navigation bar.

Now here is the real answer to the question.  To publish an article, you don't have to move it anywhere.  You just select submit on the state tab menu.  This will notify the site managers and reviewers that you want the article to be published.  The article will be reviewed to make sure it isn't broken (links, pictures, etc all visible and available) and then is published.  Now the state will show published.  Everyone will be able to see it, and it will appear in the Articles tab, and google and other search engines will be able index it also.  Published articles cannot be changed by the author, but they can be retracted (again using the state tab).  Once retracted the article can be edited, then submitted again for publishing.