Starting from 1.6, Joomla natively supports multi-languages. In other words, you do not have to install third-party extensions anymore.
To sum things up, here are the steps you need to follow:
Joomla 3.x Languages can be added from Extensions > Language Manager > Install Language.
By doing so, Joomla will add required NS Recipes language files.
This step MUST be performed if you are adding a language in which YooRecipe has been translated.
If NS Recipes is not available in your language, then you need to manually translate it. Given that NS Recipes follows Joomla coding standards, please report to Joomla documentation about translations for more information.
Simply enable the language filter plugin
Extensions > Plugin Manager > System – Language Filter
Language Switcher is a module you need to publish and assign a position so that your users can switch the language from the frontend.
You need to create a default menu item for every installed language and one additional for each language. So, with two languages, you need to create 3 menus.
After this step, you should see a star main menu and two flags for each language main menu item.
You just have to assign a language (or not) to your Categories and Recipes.