For complete documentation see the Docu Wiki Manual

Make sure you are logged in. Click on the pencil on the right of the page.

[[page_name|Link Name]]

just create a link to a non existing page and click on it

First upload file clicking on “Add images” (the button with the picture frame when editing a page) or use Media Manager
Allowed file types

{{wiki:file_name.png|Title of image}}
left aligned {{wiki:file_name.png }}
right aligned {{ wiki:file_name.png}}
centered {{ wiki:file_name.png }}

First upload file clicking on “Add images” (the button with the picture frame when editing a page) or use Media Manager
Allowed file types

{{wiki:file_name.pdf|Link Name}}

[[http://www.xxx.yyy|Link Name]]

edit the page “sidebar”