If your program is free software, there is a whole GNOME
        subproject devoted to helping you make translations, the
        GNOME
        Translation Project.
The way it works is that you upload your source code to a git repository where translators can access it, then contact the gnome-i18n mailing list and ask to have your program added to the list of modules to translate.
Then you make sure you update the file
        POTFILES.in in the
        po/ subdirectory
        (intltool-update -M can help with this) so
        that the translators always access updated
        myprogram.pot files, and simply freeze
        the strings at least a couple of days before you make a new
        release, announcing it on gnome-i18n. Depending on the number
        of strings your program contains and how popular it is, the
        translations will then start to tick in as
        languagename.po files.
Note that most language teams only consist of 1-3 persons, so if your program contains a lot of strings, it might last a while before anyone has the time to look at it. Also, most translators do not want to waste their time (translating is a very time-consuming task) so if they do not assess your project as being really serious (in the sense that it is polished and being maintained) they may decide to spend their time on some other project.