That is such a broad question...
First off do a search on Nitrous and start reading up.
Also what are your mods? What is your goal for the car? How often are you gonna be spraying?
Stiegemeier Ported Eaton and Throttle Body
DynoSpeed Racing SCT 4-bank Chip
SCT 2400 Mass Air Flow Sensor
Amazon Racing 2.80 pulley
Amazon Racing Stage 1 Air Filter Kit
Billetflow 100mm Idler Pulley
MagnaFlow 2 1/2" Cat-Back Exhaust
UPR Off-Road X-Pipe
just a few times on the dyno and at the track on on the street when i see another cobra, id like to get 600rwhp, i read an article on a zex kit on a terminator motor and it handled a 125 shot and made 630 hp, id like to run a 50 shot and put a slightly agressive tune and see if i could do that, sorry if newb