What do you need help with, exactly? Go to the wiki and register (different user db than here, sorry). Read what the home page has to say, and the Community Portal too. There are some helpful links on those pages that probably answer your questions.
Back at it's home page, change Main_Page in the URL to What_you_want_to_call_your_article (wiki will convert spaces to underscores, so just type spaces if you want). Then click the "edit" link on the page (since it doesn't exist yet). Type your info in the textbox, and click "save".