First enable the following built-in modules:
  • locale
  • content translation
In the content type settings, workflow settings, set the multilingual support to Enabled, with translation. Now, when creating or editing content, a translate tab appears which enables you to add a translation of the current content. Language packs can be downloaded from the Drupal site and extracted in Drupal's root directory. Then, in the language settings, add the languages. This will import the translations from the language packs. To make menu's language aware, install the Internationalization module, and enable the menu translation module. To place language icons automatically, install and enable the Language icons module. Make sure that in the language settings, the language negotiation is set to path prefix, with language fallback. Also make sure that every language has a path prefix. By default the english language has an empty path prefix, which may cause an unexpected language to appear.