If you have any PPL books, and are not doing a PPL groundschool refresher (a good idea that SFT always encouraged) then go over the PPL thoroughly. Knowledge shouldn't be assumed, but it helps a lot.
Also look back over some GCSE / O-level Maths and physics - algebra (formula manipulation), trigonometry, Pythagoras, electrics, forces.
[ 13 December 2001: Message edited by: Send Clowns ]