Your best resource is the Council on International Educational Exchange, or CIEE. They can set you up with an International Student ID card, and their travel branch, Council Travel (tel. 800/226-8624; www.counciltravel.com), the worlds biggest student travel agency, can get you discounts on plane tickets and the like. In New York City, they have offices at 254 Greene St., in Greenwich Village (tel. 212/254-2525); in Midtown at 205 E. 42nd St. (tel. 212/822-2700); and on the Upper West Side at 895 Amsterdam Ave. (tel. 212/666-4177).
Hostelling International-American Youth Hostels (tel. 202/783-6161; www.hiayh.org), has their largest hostel in New York City at 891 Amsterdam Ave, at 103rd Street (tel. 212/932-2300; www.hinewyork.org). Reserve well ahead because this place is always booked.