multilingual support I would like to create a content type in Drupal 7, which is available in both Italian and English. This is why I enabled multilingual support in the options of publications that allows me to choose the creation of each new node language.
But...How do I then change the choice of language in which I see the node in the web pages?
You need i18n module. It gives you a possibility to display a language switcher block on the front end.

Also check Localization update module for automatic update of translations.