Greek Orthodox Ecumenical Patriarchate of  Constantinople
Greek Orthodox Archdiocese of America 
Greek Orthodox Metropolis of New Jersey
Orthodox Church of America
Orthodox History
Church of Greece
Church of Cyprus
Directory of Greek Orthodox Churches in the United States

Monasteries:
Mt. Athos (Greece)
St. Gregory Palamas Monastery (Hayesville, Ohio USA)
Paracletos Greek Orthodox Monastery (Abbeville, SC)
Kiev-Pechersk Lavra (Kiev)
Valamo Monastery (Finland)
Preveli Monastery (Crete)

Seminaries and Graduate Institutions:
Holy Cross Greek Orthodox School of Theology, Brookline, MA
St. Vladimir's Orthodox Theological Seminary, Crestwood, NY
Christ the Saviour Seminary, Johnstown, PA
St. Tikhon's Orthodox Theological Seminary, South Canaan, PA
St. Herman's Theological Seminary, Kodiak, AK
Patriarch Athenagoras Orthodox Institute of the Graduate Theological Union, Berkeley, CA
Saint Athanasius Academy of Orthodox Theology, California

Educational & Family Services:
Religious Education Department
Saint Basil Academy - Garrison, NY
The Church of Greece Electronic Library
Trinity Children and Family Services
Theophany School
Koraes School
Orthodox Christian School Association

Retreat Centers:
Saint Basil Academy - Garrison, NY
Metropolis of Atlanta Diakonia Retreat Center - Salem, SC
St Nicholas Ranch Camp and Retreat Center - Dunlap, CA
Life Giving Spring Retreat Center - Las Vegas, NV
Antiochian Village Camp and Conference Center - Ligonier, PA

Live Internet Broadcasts:
The Divine Liturgy Live
Religious Education Orthodox School of Internet Studies (ISOS)
Orthodox Christian Network

Online Stores:
Orthodox Marketplace
Holy Cross Bookstore
Paracletos Greek Orthodox Monastery Bookstore

Online Radio and TV Stations
Come Receive the Light
Ancient Faith Radio
LYXNOS: Metropolis of Patras TV station

Other:
Syndesmos
World Council of Churches
National Council of Churches of Christ in the USA (NCC)
Orthodox Marriage Encounter
Orthodox Prison Ministry of Minnesota
Christian Churches Together
Church World Service

Bible Resources (Non-Orthodox):
Bible Atlas
Bible History
Bible Tools