IMO your CV should be taylored for each different type of job your applying for, that way it seems more relavent to the employer as they spend the 30 seconds they do to read it. In my experience, they will just have a quick browse through it and mainly go through it with you when and if you get an interview.
Best of luck Rosie.
(I spent 3 days researching on resume's & CV's a couple of years back, don't rush it and get lots of opinions from anyone you know who is the same age as the employer)
Edit: Oh yeah, and make sure when / if you get an interview you know exactly whats on the CV. As when I've interviewed people, I made sure to ask them questions on it for confirmation that they actually wrote it and not someone else