Even though it is not sufficient question, i would recommend you to go through this link which explains quite a bit on localization steps best practices.
As far as am concerned You need to localize everything you want your visitor to read.
More a visitor is able to read in his/her own language, more is the chances for them to come back. Therefore, localize all necessary thing from your visitor point of you and not yours.
Take a look at OLX , just change the language on right hand corner and see what all are localized. Its amazing!!