Idling RPM

My car has a manual transmission and when I first start it up in the mornings, the RPM (in neutral) floats around 1200 rpm but after driving for a bit (maybe even as little as 5 minutes), I notice the RPM in neutral drop down to 500 or 600 rpm. Is this normal?

Yes it is normal, cars have a ‘warm up’ phase. The engine is set to run at higher rpm’s untill it reaches operating temperature. Then the engine will slow the rpm’s to it’s idling speed.

Yes, perfectly normal.