Thanks for everyones response.
Unfortunately I don’t think my test monitor has the same resolution as the final one. I’ve just been playing around with it and it seems like a movie composition of 1440 x 1080 seems to fit well on the test screen with a resolution of 1600 x 1200, but the objects are still stretched out! I’m obviously not getting something here.
I was asked to create an .mov file which would be played using windows media player on a laptop on the day. I don’t know what a switcher and a live backup is to be honest. Where in After Effects can I specify which codec to use and could you please recommend any codecs for me?