There are two approaches to creating a new article.
Creating a new article by URL
Type in the wiki URI and add the article name to it. For example if you wanted to write an article on Wookies, you just enter this URI in your web browser:
Creating a new article by adding a new Article name
Add the name of your proposed article on the Main Page in the relevant section or to another page. For example, the syntax for a article link for Wookie would be:
If the article does not exist, it should appear in red. Follow it and on the resulting page, click on the red edit link at the top, sign in if you have to and type away. Have a gander at the editing help section on actually editing an article.
Stuff you need to do with a new article
You should make the article accessible by putting a article link on the Main Page. For example to link the the article Wookie use this syntax:
In the future you may need to add your new article to the correct category instead, but until we're using categories properly don't worry about it. It can also be handy but not vital for new articles to put something in the 'Summary' field. See the editing help section for more.