Thanks to everyone for the advice, I'm going to get the NYC Terminal chart
about a month before the trip - looks like a good time.

I had a question about the "blue" or "tower cab" route that goes right over
LGA: is that a one way deal only? Like I said I'll be coming down from HPN
southbound. I had planned to head west to the Hudson and fly right down it.
But if I can fly that other route over LGA, Central Park, then down the
Hudson, that'd be sweet.

Thanks again, Chris