Don’t expect luxury in New York City hotels. Rooms are relatively small because of the expensive real estate.
Almost always, regardless of whether you booked the hotel online or through a travel agency, you will be asked for a credit card at the time of check-in for the security deposit. This can be equal to the price of one night (sometimes less, sometimes slightly more) for possible additional expenses. The amount will be released as soon as you check out. This is a standard procedure for every traveler, regardless of where they visit from. Please keep this in mind when planning the expenses for the trip.