A good start is at Translating content argument at Drupal.org
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: