I pretty much smoke any of my cigars anytime I feel like it. Rarely, but sometimes ROTT or sometimes it will be years. In my limited experience (I'e only been smoking cigars since 2008), I've found that by and far, most NCs don't age all that well. That's not to say that they deteriorate after a prolonged time in humidor storage, but rather that there is not a significant change. Of course the exceptions would be some of the NC standard bearers, like Padron (especailly the x000 Series), Opus X, Anejos, Hemingways (the maduros), and a few other odds and ends. Where aging makes the most difference, and I think many would agree with me, is CCs. They benefit tremendously from age...even the more mild ones. Now age can vary, but from my experience all the CCs I've been able to compare are considerably better with at least a minimum of a year of age on them, and in most cases even better than that with more extended aging. That said though...cigars can be enjoyed both young and old...it really depends on what your palate is craving at the time.
I know thus far my post has been more about aging, and the OP may be looking for more info on when a recently purchased cigar is ready to smoke. To that I say this...
When I buy cigars at my local B&Ms, like others here, I will more often than not spark up the cigar right then and there. Honestly, in these instances there can be issues with the cigar as they often tend to be a bit overhumidified. This can lead to a bad/inconsistent burn requiring touch ups, or even worse...be off flavorwise, or even bitter. More often than not though, they are fine.
When I mail order cigars domestically, I will sometimes smoke one right away if it is something new that I haven't tried before, but more often than not I give them at least two weeks in the humidor. If I order from overseas, I will typically wait at least a month or more to allow the cigars to properly acclimate.
Hope that helps...