babyboeing400, as most of the respondents seem to think that how it is done in the UK must surely be a world wide standard (and if not it jolly well should be!), I'd offer the advice of checking with the CAAS. As an ATCO who has worked in the UK and Australia I'd say it doesn't make a great deal of difference at my end of the mic - UK prefers it at the end and Aus at the beginning. As long as you say something vaguely coherent as well as your callsign you shouldn't go too far wrong
