Re: Preparation for WSO training.
Times tables are the single biggest thing you can possibly practice. Get a book of mental arithmetic and work through it. Don't use a pencil and paper, use your brain and hold the figures in your head. Look at all the times tables up to 20, but really hammer the 3.5 and 7 times tables - you'll use them a lot on TANS and Dominies.
Don't bother learning any aerodynamics or anything too techy - apart from basic principles of electrics maybe - as you will be taught the subjects in the manner you they wish you to know them!
Hope this helps.
Blunty