Drupal Community Portal

I have been asked to look into the possibility of creating a website for my company that is in both English and Spanish. I have looked into various ways to do this and I think Drupal might be the best route. After looking at the Internationalization module I have a few questions.
1. I do not speak or write Spanish does this module auto translate or is there a way to auto translate, or do I have to find someone to translate the entire site to Spanish?
2. If someone posts something in Spanish such as a comment to a thread or a forum post can it be auto translated to English and the same with English comments to Spanish?
3. Are the English and Spanish versions of the site maintained and handled as one site on the back-end or does it create two copies of everything, one in English and one in Spanish.
4. Are there any good walkthrough's or how-to's for setting up a multi-language site in Drupal 7.