For whatever reason, the wiki doesn't come with any help built in. Seems wierd, but...anyway here is a little bit of help. It was part of a response to someone else on editing the wiki, so some bits of it might not be complete. If so, you can use the regular Wikipedia help article for better details.
Please correct this article if any of what I put here is wrong or can be done an easier way.
If editing an existing article, then on the "page" tab, you'd either Edit the main top seciton if there isnt' any article yet, or to add or edit other sections of an article, click the Edit link for those sections. If there aren't any sections yet, then when you Edit the main section, use the formatting like this:
== main heading title ==
*[[first section name|first section page name if article already exists]]
*[[second section name]]
**[[first subsection of second section]]
**[[second subsection of second section]]
***[[first subsection of second subsection of second section]]
***[[second subsection of second subsection of second section]]
*[[third section name]]
*[[fourth section name]]
== second heading title ==
*[[first section name]]
and so on, to add headers and sections for stuff. IIRC the number of = signs changes the size of main heading text. I think--you may have to test that.
Also, a table of contents for anything with sections like the above will be automatically generated for that page, just like it is on the main page.
Now, the way I create NEW articles rather than editing existing ones, to ENSURE the article is shown and linked correctly in the main wiki page is to edit that main wiki page, in the category I want my new page in, creating a new subsection or whatever if necessary. Then I save that page, and click the red link name for the article, which automatically creates a new article page for it, with the edit window open. THen I copy/paste whatever it is I wrote or am taking from the ES forum, etc., format it if needed (usually I don't have time so I leave that for later editors, as I figure it's better to have badly formatted stuff than not have it at all), and save the changes.