Driving in the U.K.
Except for the driving on the left thing, British road rules are similar enough to North American ones that you'll get by fine; here are the important differences
The most important rule of thumb for driving in any foreign country is this: Accept that the locals know the rules of the road—both the traffic laws and the unspoken rules—far better than you do.
Take your lead from them and drive as they do, only more slowly and tentatively.
In fact, drive with an unusual degree of caution to avoid making too many mistakes (or at least avoid making them at high speed).