http://wikitravel.org/ does a reasonable job of this. Obviously it's difficult explaining the culture of a nation in a few dozen paragraphs, and doubly so on a wiki.

For example (http://wikitravel.org/en/Britain#Respect):

    Allow some personal space between you and others in queues and elsewhere.
    You will usually find this in such places as cinemas. Generally, unless
    people know each other, you will find they will usually choose to fill up
    every row of seating and keep as much distance of possible until there is
    a requirement to sit directly next to each other. Exceptions are in very
    crowded situations where this is impossible, like on the Tube.