Driving in Boston... Dave Winer has excellent advice...
That way a wrong turn, while it will still take you miles out of your way, won't waste hours of your time.
My first night in Boston (a Friday) my buddy and I spent driving all over town. Not deliberately. We were trying to find something, a specific restaurant I think, near Fenway, because we also wanted to see Fenway Park.
The next morning I looked at a map to see where we had been. Ommagod.
I learned pretty quickly to use the T.
I learned the next best tip when I met the woman who is now my wife. In particular this: get a '62 Ford Falcon and practice getting around the Fresh Pond rotary as quickly as you can.
She named hers "Buzzy".