There's an easy to follow, step by step guide on creating wiki pages here http://www.biopowered.co.uk/wiki/Creating_pages
Or click the "Creating pages" link on the wiki main page.
You will need to be logged into the wiki using the login link at the top right of every page.
Any problems, just post on the forum and someone will help.
(http://www.biopowered.co.uk/w/images/thumb/7/75/Wiki_creating_pages.png/428px-Wiki_creating_pages.png)
(http://www.biopowered.co.uk/w/images/thumb/0/0e/Wiki_login.png/428px-Wiki_login.png)