On the Developer Tutorials site today, there's a new article post from Michael Ross walking you through the installation and creation of an online newsletter with the Drupal content management system.
There is a much better approach [than mass emails], and that is the use of a Web site that houses the newsletter and also limits reader access to paying subscribers. The ideal tool for creating such a site, is a content management system (CMS), such as Drupal, which is what we will be using in this tutorial. Specifically, we will explore how to use a forum for organizing the newsletter contents and allowing subscriber feedback, and also how to use a Drupal module for controlling subscriber access.
There's not really much in the way of actually installation help (that's what Drupal's documentation is for anyway), but he does talk about how it's initially set up, the subscription method and how to add an access-protected forum to the site to hold the newsletter information.