To see an example of how the Translation tool works once the translation plugin is activated on a page, you can visit the Main Page. You will see a new language menu bar at the bottom. It is automatically generated. Click for instance on the German link, it will get you to Main Page/de. Right under the title, you can read "This page is a translated version of a page Main Page and the translation is xx% complete." (xx being the actual percentage of translation). Click on the "translated version" link to start translation, or to update or correct the existing translation.