Hello,
At the end of my joomla installation with demo template installed the mandatory informationvof your pdf is to choose the "Default English (GB) Sample Data" but on the other side the joomla installer says install sample date none None (Required for basic native multilingual site creation).
so how can i manage that?
thks for the reply.

Please install the sample data without any special language settings.
After the installation is finished you have to setup the multi language for Joomla.
Read this:
www.templatemonster.com/help/joomla-3-x-...tilanguage-site.html

I'll try to do that but I a m afraid not to have to go home page with scroll to modules- should I duplicate the modules in another language as i will duplicate the menus and articles?

Yes, all languages need new modules, new articles, new menu items and so on....