Have you ever spent what feels like an eternity researching the correct tools for your organization, and just ended up feeling like it was just a big blur? Let us help you sort things out.
Drupal is an open-source CMS that can be customized to do nearly anything. It is powerful and modular (you can find a Drupal Module for almost anything), but does require significant developer knowledge to get started. It has a relatively steep learning curve compared to the other CMSes detailed here. However, it is a very common CMS with a large and helpful community support system.
Wordpress is a very common CMS that, like Drupal, has many plugins to customize the site and a large support community. It's more user-friendly, but less customizable and powerful. Wordpress works best for blog-centered sites.