So does the starter just delay until the glow plugs are ready? If I don't look at the glow plug light will I crank it too soon?
No, it doesn't delay. It will crank, and still start. It just takes a little more cranking to start. Technically you should wait until the glow plug light goes out before you crank on it, but it's not the end of the world if you don't. The glow plugs just aide the combustion of the fuel when the engine is cold, the compression is still what ignites it.
YES, On the PM diesel the computer does delay the engagement of the starter.
i tried few times on my PM start my engine (when engine was cold) and there was delay.
Well that is not what I am getting on mine. There is a slight delay when you turn the switch whether you wait on the glow plugs or not. Mine sure doesn't delay the starter for the several seconds that the glow plugs are heating up when I start it in cold weather.
If your concern is the remote starter turning over the engine before the glow plug light is out, most remote starters have a diesel setting which will turn on the ignition and delay cranking for 20 seconds. I had this on my 2004 Sprinter.