Thanx Larry, you say ... "you must monitor both sides" ok what am I looking for ?
I know you don't like giving out numbers since it varies depending on car / model freon etc,
but there has to be a reason for this, I have no clue.

I can't find anything like this on the cd, it's all about how to evac, rebuild, etc.

I'm pretty sure that I'm charging at the low end according to all the numbers I have seen, 30 psi should be the low end ?

In any case let's make sure, I'm using the plug that is located where the pipes get cold when the system is working. I'm NOT using the one which is really close to the radiator and the dryer. I took the car to a aircondition repair / recharge place in the beginning, that's the plug they wanted to use, so I thought I was pretty safe.

I did not want to put more on the system, it is cold enough. But I want to learn more about the system.

I really like the trick with the water for the bottle, mine became really cold, just as if it was part of the system, since I had it hooked up for a long time. I saw the warnings on the bottle DO NOT PUT UPSIDE DOWN etc did none of that.

I'm not using professional gauges, seem to be able to get them for around $75, which I will probably go for if I learn how to use them.