Welcome to the U.S.!
Done both... whale watching is a hit and miss proposition... sometimes you end up with a nice boat ride, but the price is worth it (.http://www.bostonharborcruises.com/boston-w
hale-watch/default.aspx?gclid=COags820_6sCFZA
AQAod5CKpoA
). Salem is Ok, but kinda cheesy unless you're realy into hauntings and that sort of thing (http://www.tripadvisor.com/Attractions-g6095
4-Activities-Salem_Massachusetts.html
).
I'd highly recommend doing the "Freedom Trail"... (http://www.cityofboston.gov/freedomtrail/ ) starts at Fanueil Hall in the middle of Boston and takes you (walking) to several historical and lovely highlights... such as the Old North Church ("One if by sea... etc.") The "trail" is a double row of red bricks set in the sidewalk... can't get lost.
When you get back to Fanueil Hall there's always lots going on and a true smorgasbord of places to eat. (If you like Italian, catch one of the small "Mom and Pop" hole-in-the-wall places... always excellent!) (Catch up on Fanueil Hall here:
http://www.faneuilhallmarketplace.com/ )
Have a great time! (Be sure to have a bowl of "Lobstah Chowdah"... especially if the weather is typically cold...)