http://www.noswizard.com/faq
http://www.zex.com/zx/zx-faqs/
Not sure what you mean by nozzle kit, as wet and dry kits both use nozzles, aka jets, to inject the nitrous. A wet kit injects the nitrous directly into the cylinder, mixing it with fuel and air at the same time as spark. A dry kit injects the nitrous into the intake manifold (typically) which then enters the cylinder fairly mixed, and I THINK (correct me if wrong) is a more efficient burn.
I would do no more than 100 shot on a stock motor, just for safety.
A 10# bottle should last a couple of runs I think.