http://opc.org – denominational homepage of the Orthodox Presbyterian Church
http://chmce.org/ – Home Missions site of the Orthodox Presbyterian Church
http://www.naparc.org/ – homepage of the North American Presbyterian and Reformed Council of Churches, including a “local congregation finder” by denomination
http://www.wtsbooks.com/ – Westminster bookstore: selling solid biblical and theological books, dvds, and teaching materials.
http://www.reformation21.org/ – sponsored by the Alliance of Confessing Evangelicals, exploring issues related to contemporary church life from a Reformed vantage point