Aircraft specs are part of the test material document that you have to learn, so I am assuming they will be playing a part in it.
For anything that I am having to learn, such as the document I have been using a free program called Anki, which is basically electronic flash cards. Aswell as obviously just reading through the document itself.
There is also an app for the iPhone/iPod touch which allows you to sync all your cards. So I can do them on my iPod. (very handy on a lunch time at work)
For the maths, I have just been doing the usual OASC website practice, aswell as the guide on the student room forums ( dummies guide to speed, distance, time ) which has a lot of practice questions.