Q are a race of all-powerful beings from an extradimensional plane of existence known as the Q Continuum – no, wait, that's not it. Q is just an O with a tail.
Cue – I'll just use the dictionary.com definition, because I don't think I can improve upon it: "a sensory signal used to identify experiences, facilitate memory, or organize responses." It's also the stick you hit balls with in pool/billiards.
Queue – fancy British word for a bunch of people or things lined up waiting for something.