I don't personally SCROG, but here's a bit of help..
Quote Originally Posted by bigbudzandballz
...at the internodes new shoots are growing up through the screen at about 2 to 4 inches tall...should these shoots also be tucked under the screen and allowed to "run" like the main stem...
Yeah, during veg keep doing that until the plant has covered as much of the screen as you wanted it to.

Quote Originally Posted by bigbudzandballz
....if so, what part of the plant is eventually allowed to grow up to the light...I assume it is the flowering bud that is given this privelege...
The part that you want growing through the screen is the bud sites. So when you're flowering, you'll stop tucking the growing tips under the screen and just let them do their thing.


Quote Originally Posted by bigbudzandballz
....... 8-12 inches tall and in the hundreds...will this be my case if I am growing Northen lights under a 250watt hps using a hydro system pumping nutrients?
Well your light is pretty small for hundreds of 8 inch buds! But you can always add lights when you get to the flowering stage for more bud mass.