Hi, it would help if you gave us a little info about your self.  Age, gender and etc.  Cool Running and Hal Higdon's websites have some pretty good training programs that you should look at.  If you ant special requirements you might want to find a program that adjust for them.

Tough to advise on specifics without more details about yourself. My best half is just under 2 hours. My first marathon was also the NYC marathon (I did it last year!) The biggest difference I experienced between training for a half vs. a full marathon was the increase in mileage. Your legs have to get used to running much longer distances. Some people train until they get to 21 miles. Others will go as far as training up to 26 miles!

The NYC race is relatively flat, which means it's a great starting point for running marathons. I would look into the tailored training you can get from Runner's World (don't pay for anything since you can get almost all of what you need for free - especially since this is your first!). Start with the Training Pace Calculator to estimate the different paces you'll have to associate with different types of training runs: http://www.runnersworld.com/cda/trainingcalculator/0,7169,s6-238-277-279-0-0-0-0-0,00.html and then search for their Smart Coach which will provide you a training calendar based on the finish time you're aiming for. You'll need to register for the latter.... but you don't have to pay for it