If you need a nice contact us page with a contact form including captcha to reduce spam, then QContacts might be for you.
I used it and needed to translate the field labels to another language. It was a bit of searhing, but the label names for QContacts contact page (the one you create a menu item for) can be found in this file:
Starting around line 156 there are field labels ($fld->label) in each params set. You can write your own language labels in this file but it would be wiser to use a Joomla translation text (e.g. QCONTACTS_NAME) here and add them to your language files aswell (if your site is multilanguage).