When you switched the power on after wiring up and the light came on you probably felt pleased... When you operated the switch and the fuse/braker blew you probably felt less pleased...
What you did with the switch was not to switch it off but to switch it ON! With the switch set to On a wiring error at the ceiling directly connected Live to Neutral with no light bulb for a load - the fuse/breaker turned everything off for you.
You will notice the Brown wire in the picture running off to the switch - it carries the Live mains voltage - when the switch is in the ON position the Live coming back from the switch is called Switched Live but it comes back on a Blue wire in this drawing and it looks a bit like a Neutral wire - notice the Brown sleeve on the Blue wire on the extreme right - this is to show that it's not what you might think it is - it's not a Neutral but Switched Live, scary and dangerous.
You will notice in the picture that Permanent Live is not connected to the light bulb - just switched Live goes to the bulb.
If all this is too much then an electrician should be called.
