QUOTE(playthestatic @ Jan 2 2009, 09:46 AM)
I like to think I'm relatively well-prepared, but I really have no idea what to expect. How strict is the examiner going to be? Will I lose many marks if I get a note slightly out of tune? How difficult is it to get a merit or a distinction? Do you have to be mind-blowingly good to obtain the latter?
I took my first ever exam (G3 oboe) in December and got a distinction. I am NOT "mind-blowingly good". I was about as well prepared as I thought I was ever likely to be, thanks to good teaching and plenty of practice. The important bit in your pieces is musicality. You get high marks for a convincing performance - keep going, even if you slip up here and there. I messed up a couple of quaver runs in one piece and I'm sure my intonation wasn't spot on but the examiner did make positive comments about ensemble with the piano and articulation.
I agree with sbhoa, read and understand the marking scheme. Do bear in mind how many marks are up for grabs in scales, sight reading and aural. Even with high marks in your pieces these can let you down. I'm often surprised by comments on the forums about scale and arpeggios letting people down in exams. These are not hard to prepare - they just need work. No I didn't get top marks for them, I still managed to mess up two arps.
Do regular work on sight reading and aural and get your teacher to give you a mock exam complete with marking sheet and comments. Good preparation will give you a chance of getting into the exam in a reasonably relaxed frame of mind and that alone will be worth a few marks.