This days I am dealing with a Drupal multilingual installation which could be difficult if don’t know how it works. Drupal speaks over 100 languages, perhaps you know already. It comes obviously with English like native language.
All modules has to be downloaded and installed from the web interface or by uploading all in the yoursite.ext/public_html/sites/all/modules/ folder
Some dependencies (for example Locale or Content translations) has to be checked to enable all modules.
After it has to be enabled in the yoursite.ext/admin/structure/types all the type of contents that will be translated from the native language.
Best practice is to set at multilingual settings:
and also enable multilingual support for this content type. If enabled, a language selection field will be added to the editing form, allowing you to select from one of the enabled languages. You can also turn on translation for this content type, which lets you have content translated to any of the installed languages. If disabled, new posts are saved with the default language.