I am replacing my bathroom light and I am quite puzzled.... The new light has a blue and a brown cables but I only have 2 brown cables coming down from the ceiling. Any clues?
As long as you have only 2 wires coming out of the ceiling, in won't matter which way you wire it. The bulb will light no matter which side is live or neutral.
I agree with sddsddean, but please make sure that you are putting the circut breaker off before working on the system and not just relying on the light switch being off.