Disable the Content Guide which opens when you open Quicktime
An overview of the Quicktime preferences
Choose to open new movies you open in the same Quicktime window, instead of a new window for each movie
Choose to have movies play automatically when opened in Quicktime
Look at your options for while in full screen, movie size, background color, controls and more
Choose to show CC and subtitles during the playing of videos when they're available
A look at your sound options for Quicktime