Hey buddy Im in NYC as well heres the answer.
Go to 260 Broadway on the 5th floor, its the IRS
ask for a tax ID #...its free and on the spot
and thats it...you are in business.
now every 3 months, that would be January, April, July, October by the 15th, you will do your taxes both federal and state, the form you will fill out on top of your usual tax form has a number to it, i forget what its called BUT the IRS will tell you right on the spot when you get your Tax ID# which takes 2 minutes.
So now what?
You are in business , just remember to put away at lest 30% of what you make to cover taxes and you are in good shape.