It's named for Boston, England, which had a sizeable population of Puritans - the people who settled the place. "Boston" itself is a shortening of "St. Botolph's Town." Also, the original name for Boston was Tremontaine, in honor of the three hills that were the first thing you would see on the Shawmut Peninsula. Two of the hills no longer exist (they were flattened in part to supply fill for the Back Bay); the third is Beacon Hill, which itself was shortened. The original name survives in Tremont Street. You can read more about the original Boston on the U.K. version of Boston Online.
I'm visiting Boston for the first time. What should I see? Exactly what depends on what your interests are, but what follows is a basic two-day Boston Experience. All of the locations listed are easily accessible by subway (known around here as the T). Taking the T to get around the city is an excellent idea - it's reliable, safe and inexpensive ($1 a trip, or you can get a visitor's pass for unlimited travel). Boston roads and drivers, in contrast, really are as bad as the natives will tell you. Keep your car in the hotel garage. The Freedom Trail Boston played a critical role in the Revolution, from the Boston Massacre to the Boston Tea Party to Paul Revere's ride [More history info] The Freedom Trail is a 2.5-mile red line in the sidewalk that links 18 historic sites downtown and in Charlestown.