For theme options, I recommend reading:
http://polylang.wordpress.com/documentation/documentation-for-developers/functions-reference/#pll_register_string
and
http://polylang.wordpress.com/documentation/documentation-for-developers/the-wpml-language-configuration-file/
For strings in templates:
http://polylang.wordpress.com/documentation/setting-up-a-wordpress-multilingual-site-with-polylang/theme-internationalization-i18n-and-localization-l10n/