What's the best website for teachers to post assignments, class notes, and other class info on?

I teach college French, and I'd like to put together a website that my classes can go to for updates and help. I'm not looking for a place to post grades, just a place where I can post assignments and due dates, class notes, links to helpful websites, and such. It might be helpful to have a message board where students can discuss things, ask questions, and help each other, too.

Is it best to use a full website, a message board, a teacher's assignment website, or some other configuration? Let me know what has worked best for you.