Don't be late!
For any reason. The Met observes a strict seating policy. Latecomers are not admitted until the end of the first act. Until then, they sit on a bench in a little room watching the first act (or the whole of that night's opera, if it's "Salome," "Elektra," "Wozzeck," or "Das Rheingold") on closed-circuit television with middling sound quality--and that's not what you paid for, is it? Try to get to the theater anywhere from 10 to 30 minutes early--the doors open a half hour before the curtain goes up.

Getting There
If you're driving, get to Lincoln Center an hour before curtain time to find space in the Lincoln Center Garage--a must during inclement weather. Pay for your parking before the performance, at the little booth on the concourse level. If that garage is full, try on the north side of 65th Street.

By subway, take the 1 or 9 to 66th Street-Lincoln Center. There's an entrance into the Lincoln Center complex at the south end of the downtown platform, and a tunnel leading to that entrance at the south end of the uptown platform. Walk through the turnstile, up the ramp, and hang a right--the tunnels go under the plaza to the concourse area. From there, make a left, and enter the opera house through the glass doors across from the Performing Arts Shop. Alternatively, go up the escalator at the north end of the concourse--it leads to the Met lobby, the box office, and the Metropolitan Opera Shop. By the way-- you may have to wait on line if you enter through the concourse, but I recommend it anyway--the crush in the Met lobby is best avoided.

What to bring:
Your ears and eyes.
Opera glasses--especially if you're sitting in the balcony or higher.
Breath mints/cough drops/sour candies--because everyone has coughing fits at the opera.
A pack of tissues--the Puffs packs that open silently are a great invention.
Leather, horned helmet (optional, seen at the last Met staging of "The Ring")

What NOT to bring:
Laser pointer.
Air horn.
Giant orange foam cowboy hat.
Also: Turn off your watch alarm, disable your beeper, and turn the ringer off on your cell phone. You can use them again at intermission to show fellow audience members that you're with-it and in demand.

Meet the singers!
Yes, like any theater, it's possible to meet your operatic heroes at the Met. The stage entrance is located in the parking garage--through the glass doors at the north end of the Lincoln Center concourse.

Additionally:
The Metropolitan Opera Guild schedules a yearly series of in-store appearances in the Performing Arts Shop (located on the concourse, across from Founder's Hall) and in the Metropolitan Opera Shop (in the Met lobby, right across from the box office).