I’ve noticed that some Czechs have titles both before and after their name – like Dr. Jan Novak, Ph.D.. Why?

Like their German neighbors, Czechs are obsessed with titles and so rather than follow the American habit of just indicating the highest degree they’ve achieved, they often like to show multiple achievements. You can find some of the more common titles and their placements at the following websites:
http://cs.wikipedia.org/wiki/Titul
http://www.ujc.cas.cz/poradna/odpo.html#akad