If you are flying in, the useful thing to know is that London works differently to most American cities, both legally and socially. Arranging something before you land is normal here, and it is by far the easier way to do it.
Arrange it before you fly
The best diaries in central London are booked days ahead, not hours. If you want a particular person on a particular night, message while you are still at home. Time zones are not an obstacle, since almost everything is arranged by message rather than by phone.
Give your dates, the area you are staying in, and whether you want outcall to your hotel. That is enough to get a straight answer about availability.
Outcall is the visitor’s option
Come to London and you will be staying in a hotel, which makes outcall the obvious arrangement. You are not finding an unfamiliar address in an unfamiliar city late at night, and London hotels are entirely used to guests receiving visitors.
Read the incall and outcall guide for the practical detail, including what to do at reception and what the serviced apartment blocks in Canary Wharf expect.
Distances are not what you expect
London is slow. Two miles across the centre can take forty minutes in an evening, which is why every listing here leads with how far away she is rather than just naming an area. If you do not know the city, the mileage figure is the number to read. Area names will not help you judge anything.
Money
Cash, in pounds, agreed in advance. Tipping is not expected on top of the fee in the way it is at home. Rates are shown here in both currencies so you are not doing arithmetic while you browse, and the rates guide covers the bands by area.
A note on the law
The legal position in the United Kingdom is genuinely different to most of the United States, and the differences are not intuitive. This is worth understanding properly rather than assuming, and it is not something a directory should be your source for. If it matters to you, read the current position from a reliable legal source before you travel.