Multilingual Website Approch

Hi all

i want to create a multilingual website where a user can select his language and he can see website in his language.i had read localisation and 3 yii approch but i wasn’t able to reach a i have following questions.

(1) what is the best approch for multilingual site?

(2) do i have to translate all the content on my website?

(3) what about content inside i need different version for each language?

thanks in advance.