Re: 1/4 moa
The click correction was addressed already. As for your dots:
You'll want to refer to the Nikon manual for spacing on the circles in their BDC reticle. If I remember correctly, each circle subtends 2 MOA when on the maximum power for the scope. That means at 100 yds, it covers ~2 inches, at 200 yds ~4 inches, and so forth. The distance between circles, though, I don't remember so check the manual (it's also available on Nikon's website). You'd need to figure out the drop of your load, and then you can use the appropriate circle (I use top, bottom, and middle to gain extra aiming points and more precision) to hold on targets at various ranges beyond your zero range.