Enrico Zini's Mime type associations (via Planet Debian) is about the practical side of fixing MIME type associations so that various types of files open in the right program on your Debian system. This is an area of interest to me, but I've never pulled everything together into one spot (and compactly) the way this article does.

(For my entries, there's how xdg-mime searches for MIME type handlers, how xdg-open picks which web browser to use, the basics of /etc/mailcap, and a cautionary story of mailcap handling.)