This is the main wiki page. For adding other pages to the wiki, you need to login then go to 'Create Content --> Wiki page' from the user navigation menu.

A Wiki is a collaborative writing effort: users can collaborate writing the same pages of the book and reviewing or modifying pages previously written. So when you have some information to share or when you read a page of the wiki and you didn't like it, or if you think a certain page could have been written better, you can do something about it.