As you can guess I'm taking the exam next week!
I have used the G5 Theory in Practice book but it mentions additional information being needed ie knowledge of instruments and the orchestra etc. I was wondering if there are any links via the internet on this knowledge as I don't know v. much about it as I haven't done GCSE Music! (PANIC!) Thank you for any replies!

I wonder if this is the kind of thing that would help ?

http://www.dolmetsch.com/musictheory29.htm