Whats goin on everyone?

I am exited and a bit nervous. My father is letting me work on his 1964 Porsche 356 SC Cabriolet. Whooo hooo! anyways...

My question is, when you are tuning the idle circuit, what symptoms conotate, or in plain english, when do I have to adjust the idle "air bleed"? The Webers (IDF series, I am pretty sure its model 44) have a mixture and idle speed screws (of which I am familiar) but I have not dealt with an "idle air bleed" before. Do you use it when you want to super fine tune the idle after the mixture has been set? I know its used to let air bleed in so the engine will idle smoothly but how do I know if the devil is misadjusted ?

Thanks in advance,
-CJP