One of the classic articles on coffeehouse culture is Steve Pincus's "''Coffee Politicians Does Create': Coffeehouses and Restoration Political Culture" in the Journal of Modern History (1995). Basically, coffeehouses were a hotbed of political, religious, and cultural conversation in both Britain and British North America.

Pincus writes:

"As soon as a customer set foot in the coffeehouse, the coffee master greeted him or her familiarly, asking, "What news have you, master?" or, more poetically, "What news from Tripoli? Do the week's pamphlets in their works agree?" or proclaiming, "Here's fresh news from all parts." Upon entering the rooms one was "not thrust into a box, / as taverns to catch the fox." Instead one sat at "a table of an acre long covered with nothing but tobacco-pipes and pamphlets." Not only pamphlets but also a "store of mercuries [newspapers]," "the last coffee letter," and the latest "lampoons and satyrs" could be found both in city coffeehouses and "in the country too." Indeed, one Londoner claimed that "there's nothing done in world, / From monarch to the mouse; / But every day or night 'tis hurl'd / Into the coffee-house." The coffeehouse was truly "the mint of intelligence," the "exchange where haberdashers of political small-wares meet." (819-20)

There are actually coffeehouse tours in London led by Dr. Matthew Green that I've heard are really enjoyable. As for the coffee itself, it's apparently absolutely disgusting.