Hi! Let me see if I can help you here.
When you go to your profile in the Archives, you should see a dark brown area in the upper right corner. If you're not logged in, this is where you'll input your email address and password to log in. Once you ARE logged in, you should see some options. The center one is Control Panel.
If you click on that, you will be taken to a page that allows you to do many things. You can edit your profile, manage your recommended reading and favorite authors, and if you scroll down, you'll see all our archives listed on the left side.
Each archive has some options in this view, and the one you want is Add, which will allow you to upload a new story to the archive. Make sure you're using the add button for the correct sub-domain, for example, "Harry Potter." Otherwise, it defaults to Anime, and new misplaced stories are deleted without notice. In future, when you want to add a chapter, or edit your story, you'll return to the Control Panel and use the Edit option.
You can always ask here if you find something confusing, and we'll do our best to help you out.