Directions from New York City and the three major NY/NJ airports to
the Rutgers Department of Linguistics by mass transit:

1. From John F. Kennedy International Airport:

Take the LIRR [Long Island RailRoad] to Penn Station in New York City.
Currently, this costs $5 plus a $2 metro card.
For details, consult this page.
Then, take the NJ Transit train from Penn Station to New Brunswick (see 3 below).

2. From La Guardia Airport:

Take the M60 bus ($1.50, payable in cash or with MetroCard) to
125th St and St Nicholas Ave, Manhattan.
Take the C or A train downtown (free transfer if you used MetroCard
on the bus, otherwise $1.50) to 34th St/Penn Station (if you want
to continue by train) or to 42nd St/Port Authority (if you want to
continue by bus).
Follow the directions from New York City in 3.

3. From New York City:

Best way: by train. From Penn Station (8th Ave and 33rd St) take NJ Transit's
Northeast Corridor line (final destination Trenton) to New Brunswick.
You can buy tickets from a vending machine.

By bus (but why?): From Port Authority Bus Terminal (8th Ave and 41st St) take
Suburban Transit to New Brunswick, and get off at the New Brunswick
train station. Buses usually depart from gates 420 and 421 in the
South Building. Tickets are $5.55 one way, $10.80 round trip, and
have to be bought in advance at the ticket windows on the ground
level.

4. From Newark International Airport:

Take the NJT train from the Newark International Airport station.
All southward-tending trains stop in New Brunswick.
To get to the train station, take the monorail from inside the airport.

5. From the New Brunswick train station to the Linguistics Department:

Walk. If you come by train, exit at the front end of the platform
and you'll find yourself on Easton Avenue; if you come by bus, walk
up the street until the traffic light, that's Easton Avenue. Turn
right and walk up Easton to the first light. Turn right to Somerset
Street for one block. Turn left to College Avenue for two (rather
long) blocks. Turn right to Seminary place. The department is at 18
Seminary Place, which is a yellowish house on your right. The whole
walk should take 5-10 minutes.
In case you don't want to walk, you'll find a taxi stand as you
exit the train station. A taxi to the department should cost $3-$5.

Web sites:

New York City Transit (subway and bus):
http://www.mta.nyc.ny.us/nyct/index.html

NJ Transit (trains):
http://www.nj.com/njtransit/

Suburban Transit (bus):
http://www.suburbantransit.com/content.html

Airports:

JFK:      http://www.panynj.gov/kennedyairport/
La Guardia:   http://www.panynj.gov/laguardiaairport/
Newark:   http://www.panynj.gov/newarkairport/