I've only sold one to date, but followed much advice on this site before doing so.

1) As a 1st sale, I would only start local through either Pinside classified or Craigslist. If priced right and somewhat desirable, you shouldn't have too much trouble finding a local buyer (especially in NY).
2) If you have an offer from someone you don't know, have the pin in a location for the buyer to look at that you are comfortable with. If you are not comfortable having a stranger in your home, move the pin to your garage. Just make sure it is set up so the buyer can play a few games and inspect.
3) Cash, cash, cash. Almost any other form of payment comes with risk. Be upfront with this requirement and don't deviate no matter how nice they are (unless you absolutely know the person you are dealing with). Any serious buyer should have no issue with this form of payment.
4) Be upfront with the buyer on any issues with the pin, will save headaches in the future.
5) Make it clear that the buyer is taking possession of the pin "as is" with no expressed warranty. I wrote up a couple of lines on a piece of paper detailing this along with the purchase price for both parties to sign as a "receipt".
6) Have cash in your hand before moving the pin into their vehicle.
7) If it's in a weird location and requires steps, you may want to make it clear that the buyer needs to bring people with him to move the pin. Remember, once he gives you the cash he owns it so any damage when moving it would be his responsibility.

Scott