I own a 7 openerp server and file translation type po. I looked at all the guides that I have seen under the "Settings" sub category "Translations" option should appear I import / export, while I just listed the "Load Translations"
What should I do to load the translation?
Option Load Translation Loads from all modules from every *.po file in selected language. If you take 'Override' option then it override existing terms. My experience tells me that is not a good methods. If you have your own translations, terms than after that these terms will be overrided by the defaults.
Option Import Translation Most preferable. You know what translates will be overriden and which not because you know your file.
To see the results of imported translations you must restart openerp server. I've noticed also that update/install module also influences on import results. You can try this method without restart your openerp instance, but I wont give you confidence :)
It depends what kind of translations you got. If you got translations for your own module, then there is no worries and any mentioned import method should work (either directly putting translation file in in18 directory, because no one else should overwrite your translations.
But if it's for standard module. Then you should look at this: https://doc.odoo.com/v6.1/contribute/07_improving_translations.html/ (but this might change as new version is coming out and Odoo switched / switching to git).
