Princess,
Call BA TEP recruitment on 0870 607 3777 ( that's +44 870 607 3777 if you happen to be outside the UK). They'll ask you a series of questions and if you're elligble, send you a form.
Agreed, WGW's notes are good. Also you might think about photocopying the form before writing on it. Fill out the copy first, to ensure it fits in the space provided. Be a downer if you get to the end of a question and run out of..
Best of luck,
ATCS