Sierra Hotel's advice is good. I was going to say you should try getting the ground school stuff out of the way; then I remembered that the exams are only valid for 12 months until you have to take them again. That's not to say you couldn't start reading through the books and getting to grips with some of the more tricky stuff.
It might even be advantageous to read through Book 1 so that you're ready for your first lessons. If you can go up for a ride in the right hand seat, take the opportunity. It certainly helped me out doing so before starting working towards my licence.