First add a language label. It will look something like this:
lbl_your_text_label
To insert is, you may have to edit some templates. For example you want to use this label for a menu:
And include the label in the template like this: {$lng.lbl_you_text_label}
And then if you want to use the label with a link / url do it like this:
<A href="your url here">{$lng.lbl_your_text_label}</A><BR>
That should do the trick. It only works in templates, not the php files.
Hope this gives you a start..