1) Adding additional languages or cultures to a website requires setting up the proper configurations in the site manager. This includes adding the new cultures and selecting which documents need translation.
2) Content then needs to be translated by selecting the appropriate language in the content tree and localization toolbar. Translated versions of pages are indicated by flags.
3) It is best practice to make language selection easy for users on the site and to acquire backlinks from target countries to help with SEO for different language versions.