Help:Links
Internal links, also called "wikilinks" are basically the most important part of wikis! They are those blue texty things that let you go from one page to another. Like this li'l guy. Have you ever spent hours on Wikipedia clicking from article to article, learning all you ever wanted to know about early 20th century burlesque dancers? Me neither, but you get the idea. Links are important, because they could be the only way people will find pages.
It is ridiculously easy to add a link. If you know the title of the article, like "Portlandia", it's as simple as putting two pairs of square brackets (these guys: [[ ]], usually near your P key) around the title, like this: [[Portlandia]]. Try it and it will result in the following link: Portlandia.
Fancier linking
If you don't want to use the page title as the word you link, like: that huge bronze woman, it's as simple as using a bar symbol (this guy: |, usually on your \ key) between the page title and the linked text. Like this: [[Portlandia|that huge bronze woman]].