To translate taxonomy terms you should use the Taxonomy translation module (part of the Internationalization package). There are three translation mode for taxonony vocabularies and their terms. If you want to keep the same terms but translate their titles (and description), you should set your vocabulary mode to Localize terms. When doing this, enter each term in the site default language (probably Egnlish in your case). Then, using the translate strings interface, you can provide translations.
Check the Multilingual Taxonomy handbook page for more information.
The Taxonomy translation module should handle standard term displays so they will use translations. If you need to retrieve a term's name and description for output in some custom code, you will have to use i18ntaxonomy_localize_terms
to get the translations. Passing the term's name or description to l()
won't work.