Anyone can edit pages in this Site, it is open, simply click on edit button at the bottom of the page. This will open an editor with a toolbar pallette with options.
To create a link to a new page, type the name of the new page into the box on the left nav bar. Once you have created a new page you can link to it using syntax: [[[new page name]]] or [[[new page name | text to display]]]. Follow the link (which should have a different color if page does not exist) and create a new page and edit it!
If abusive editing is discovered, pages will be reverted to earlier versions.
Although creating and editing pages is easy, there are a lot more options that allows creating powerful sites. Please visit Documentation pages to learn more.