At the Articles main page, click on the 'edit' tab at the top of the page. You will then go to an editing panel that has the "source code" of the page. You'll see the list of articles in double brackets like this:
[[Article 1's Name]]
[[Article 2's Name]]
The double brackets mean that they are links. Just think of a name for your article and type it in at the bottom of the list, putting it in double brackets. The click the "Save page" button at the bottom of the page. You will then go back to the normal Articles main page. Then click on your newly created link. You'll be presented with another editing panel, this time for your article. Cut and paste the text of your article into the panel and then go to work. Simply click Save page every now and then to save your article. Once your article is saved, you can just click the 'edit' tab at the top of the page to begin editing it again.