Travelling through Schengen countries before entry to Spain on student visa

Hello,

I'm from Australia and I will be studying in Spain for a year, starting in September 2012.
I would like to travel around Europe (including Schengen countries) for two months before my studies begin (so I plan enter the Schengen area in July).
Does anyone know if it is possible for me to do this?

I am a bit confused as to whether the 30 days I have to register for the residence card begins when I:
- enter Spain; or
- enter Schengen area; or
- enter the EU.

Can anyone help me?

Thanks