Ok so for things like products, you can edit the text shown per store by editing a product and then changing the store view from the menu on the top left.
Static text should be done using locale files. For example; if you look in app/locale/en_US (which is the default language) you will see a bunch of csv files. Whenever Magento sees a string like $this->__('Login') it will go these files to see what it should translate it to. Obviously translations do not have to be language based they can just be something else you want appear whenever the word 'Login' is used.
If you have set another language then you will need a folder app/locale/<name> with the corresponding csvs.
Actually, here is a reference post
Hope this helps 
