I was wondering what kind of results you can get as a single shot (raw) straight out of the camera without any post-processing (even just stars, stills no trails), so when i see my images on the camera after the shot i can actually understand if i'm going the right way or not (I am a fan of the good old trial and error...); how many stars are actually visible? how many are just luminance noise for the high iso/long exposure?
As a few examples have shown, you'll definitely know if you got it right from your LCD. I always use the same lens and am within a few days of a new moon, so I can fairly reliably use the same settings for every shot. For me, it's always (at 11mm on a 60D) 30s at f/2.8 and ISO1600. If I was using a 5dII, I might also try those same settings at ISO3200, to get the stars and milky way to pop more.
You'll definitely have to do some processing to really get the saturation and lighting right...but, it should be pretty clear in your display that you have the milky way and stars. Otherwise you'll have to raise the exposure 2+ EV, and it'll look awful
Also, if you are dealing with a new moon, you'll like either need to light paint your foreground, or shoot a separate exposure. Sometimes its a 2-3min exposure needed to make it look good