Originally Posted by jambo

OK, You clearly have some juice left in the battery if all the lights are OK. So either:
1) The battery's just not got enough poke to start the bike. If this happens you will usually here a clicking down by the rider's seat as the starter motor relay engages and dis-engages.
2) The starter switch isn't engaging the relay. This can be down to corroded contacts but before you go nuts pulling things apart check that:
-The kill switch on the right handle bar is set to run (honestly, we've all done it)
-The bike is in neutral
-The clutch is pulled in

If this doesn't help there is a switch connected to the clutch lever and the side stand, bypass both with a bit of wire in case the safety switches have given up, try again. If this doesn't help check that the contacts for the starter switch itself haven't corroded up by taking it apart and cleaning it up. Be a bit careful if you're doing this as there's lots of springs and little bits of plastic and metal. It's a bit of a jigsaw, take lots of pictures as it comes apart

Further words of wisdom to follow from others....

Jambo