"WordPress is a state-of-the-art semantic personal publishing platform with a focus on aesthetics, web standards, and usability. What a mouthful. WordPress is both free and priceless at the same time.
More simply, Wordpress is what you use when you want to work with your blogging software, not fight it."
We use WordPress in our class blogging exercises. Simple to setup, the process takes about 5-15 minutes. WordPress is perhaps the easiest, yet most powerful, CMS we have encountered, thsu far.
Visit WordPress.