Magento: How To Set Up Multiple Languages in Magento

In order to configure a different language for your store, you need to follow a simple procedure:

1. First go to http://www.magentocommerce.com/translations, where you will find various language translations packs for default Magento interface.
        Download the language pack for the desired language, extract and paste the extracted files to respective places in your Magento directory.
         or
You can install it directly by searching and installing through Magento Connect.

2. Now go to Admin Panel, then go to System --> Manage Stores.

        Click on Create Store View button.
Select Store, provide appropriate value for Name and code, and select Enabled from Status dropdown. Click on Save Store View button.

3. Now go to System --> Configuration and Select Store View (which you created in step #2).
Clicking on General tab (on left side), you will see Locale Options on right side. Select installed Language from Locale dropdown. Save Config.

and you are done. Just Clear Magento Cache Storage and see reflection on frontend of you website.