I'm starting/finishing my PPL in about 3-4 months...I can only imagine how excited you're feeling!

I have some previous experience, 10 hrs of flight but I've learnt a great deal, Its basically what everyone has been telling you...Self Study and make sure you have a general understanding of what you will be doing once you're in the aircraft.

Get some chair practice, If possible and allowed, with your instructors permission, you can get there a bit earlier than him, preflight and go thru the checklist yourself until you're familiar with the buttons in the cockpit while you're on the ground, saving both time and money!

Good Luck with your training and let us know how it goes when you do start!