London Night & Day, edited by Sam Lambert and (the headline act) illustrated by Osbert Lancaster, was intended to help visitors to London during the Festival of Britain and, of course, contains a section on pubs.
It is written for complete newbies and so explains in minute detail things which would probably have seemed obvious at the time. To readers 65 years on, however, this detail is extremely helpful. For example, though the pint is very much the default measure these days, our anonymous advisor says:
You order… by asking simply for a bitter, a mild or a Burton and you will be given a half-pint. If you want a pint you must say so.
The default type — what you get when you ask for just ‘beer’ — was, apparently ‘mild ale, which is also called “wallop” and is the cheapest and weakest… and maybe not what you expected’.
There is the usual breakdown of the main types of bar within a pub (public, saloon, jug-and-bottle) and of the most commonly found beer in bottles (light ale, brown, Guinness, Bass, White Shield Worthington).