To add an article, you need to login and go to /admin - click 'Article' and then the 'Add Article' button at the top (in the green bar, not the main navigation).
thanks for your answer - this means that only an admin can add articles - ok...
But is there a chance to let also a normal user add articles? I changed the ARTICLES PERMISSIONS -->article_add_article-->checked for all users (except guests) - but unfortunately it doesn`t work how I want.....
You have to remember there is no such thing as admin - it's just users in a group that happens to be called 'admin' (or 'root' for the overall user) which have more permissions than others.
How doesn't it work the way you want? You can always link people to example.org/article/config once logged in as well.