A visit to Boston requires as much or as little forethought as you want, taking into account one important general rule: The later you plan, the more you'll pay. That isn't strictly true in the depths of winter, but for the other 46 or so weeks of the year, you'll most likely find yourself balancing spontaneity against thriftiness.
Getting your bearings is famously difficult, thanks mostly to the baffling street pattern (urban legend says it originated as a network of cow paths, but the layout owes more to 17th-century London and to Boston's original shoreline); we will help you start getting acclimated. Here I'll also fill you in on the unpredictable climate and the events, festivals, and parades that can help make your trip even more memorable.