What are some important modules I should install in Drupal if I am going to use it for a news website.
Picxelplay is right, but that said, you may want to check out Open Publish, a Drupal distribution aimed at newspapers and the like.
For a news site you're probably, at the very least, wanting:
CCK- gives you the ability to create custom nodes
pathauto- allows the automatic creation of human readable urls
views- very versatile module that lets you create aggregates of content based on rules and restriction
Panels- lets you group different pieces of drupal structures on one page (a view, a node and a search form on the same page)
I think the first step is to get your roles set up properly as to who's allowed to do what etc. And, yes, more information would be much more helpful.