My usual response to "Can Drupal do X?" is "Drupal can do anything!"  Usually the tougher question is figuring out just how to do X in the sea of configuration options and modules available. 

Drupal’s site itself has a site recipes section (read carefully, some can be a bit out of date), and there are other such tutorials out there on the web (just add in a keyword for the kind of site you’re trying to build). Below are a few links to Drupal Recipes for several common website styles.

How to Build a Question/Answers Site in Drupal

• This tutorial covers setting up a question/answers atmosphere like Yahoo Answers in which anyone may answer a posted question
• There is no coding or modules required - perfect for those very new to drupal.

How to Create a Wiki Style Site in Drupal

• This tutorial covers setting up a Wiki Style Website
• There is no coding, however the Liquid module is required with some configuration

How to Create a Private Forum and member-only site in Drupal

• This tutorial gives an excellent walk-through for creating a private forum for members only in Drupal 5.x.
• Also covered are how-to’s for forum moderators, private-side websites and how to view the list of forum mods

How to Create an Extracurricular Website in Drupal

• This tutorial covers setting up a basic website for anything sports or club-related in Drupal 5.x
• Several modules are required but there is a very easy-to-follow tutorial

How to Create a Personal Website in Drupal

• This tutorial shows what is needed to set up a personal website in Drupal 5.x
• There are several modules required, however, there is an in-depth walkthrough included

How to Create a Drupal Podcasting Website with only Core Modules

• Just to show that Drupal core by itself can still do a lot, here’s a tutorial for a podcast site that doesn’t use additional modules
• For Drupal 5, but steps would be the same for Drupal 6