The stage 1 booklet is there to be read and studied. However so far I don't think anyone has been asked in detail questions during stage 1, they're of a more general nature. Having said that though if you get accepted you will have to learn even more details about aircraft so you might as well get started erly IMO.
I have no clue if the SDM is still around (I did my stage 2 before DART came around) but hope it is because it was good fun
