One thing not handled in Richard's method is that the first word after a colon or dash must be capitalized even if it's a small word.  E.g.:

     Star Trek 4: The Voyage Home

Not

     Star Trek 4: the Voyage Home.

There are other capitalization rules that make this tough to code.  From my experience, it's better to avoid having to do this at all, and make sure you get good data at the point of data entry or data import.  For my movie database, I enter titles by importing or copying and pasting straight from the sources that already use correct capitalization instead of manually typing them in.