You can download more language files from the joomla.org. I would suggest reading their documentation on this as this relates directly to the cms itself, not a template.
But the language files of official joomla site, only changes the backend, isn't it? I need to translate the front end of my template. Words as for exapmple "read more" and this kind of things.
Moreover, its no spanish translation for joomla 2.5. I need to do this manually. But How? Where are located the words than I need to change? In the data base or where?