Taking a gap year between school and university can be a very good thing but you need to make sure that your chosen universities (and course tutors) agree.
The university prospectus may welcome students who are taking a year out, while one of its departments doesn’t (or maybe insists that the time is spent gaining relevant experience). Before you apply, ask the admissions tutors to spell out the university and departmental position, and whether others on your course will also have taken one.
If you decide to take a year out, you have a choice as to when to apply for your course. Either you apply during your gap year, when you have taken all your exams, along with everyone else applying for that year. Or you apply the year before (so, usually, in your last year at school) for deferred entry – so, for example, apply in autumn 2012 for entry in 2014. Watch out for those universities (and departments) that are happy about gap years in principle but do not offer places to applicants for deferred entry.