There are a lot of schools out there that are reputable. There are also a lot of schools out there that are run by guys who think they know things. Research the trainer/company you're interested in. How far are you willing to travel? What background and experience in shooting do you have? Have you taken any prior courses? Prior mil or LE?
Also, check out then tactical pistol club mentioned few threads down. This will get you shooting in some tactical scenarios, instead of just target shooting. It's not too far from the bronx either. But I recommend some training/practice first, before coming to the club. It would be overwhelming and unsafe in my opinion to be doing practical shooting scenarios out of the bat. But if you been shooting a while then it'll be a hoot.