The Episcopal Church has a dedicated page on the church's response, including how to help. Episcopal Relief and Development has bulletin inserts (half page, full page). And Presiding Bishop Katharine Jefferts Schori has made a video statement.
The Catholic Church is Haiti was dealt a severe blow:
"The lifeless body of Archbishop Joseph Miot of Port-au-Prince was found this morning under the rubble of the archbishops' residence," L'Osservatore Romano said in a Page 1 story Jan. 13.80 percent of Haitians are Roman Catholics. The church in Haiti dates from the 1500s.
Archbishop Bernardito Auza, the Vatican's apostolic nuncio in Haiti, told the Vatican missionary news agency Fides: "Port-au-Prince is completely devastated. The cathedral and the archbishop's residence, all the big churches, all the seminaries are reduced to rubble."
He said a study institute for men and women religious had collapsed, with many students inside as they attended a conference. The nunciature withstood the quake, and there were no injuries there, he said.
The Evangelical Lutheran Church in America has information about Haiti, links, and liturgy resources. United Methodist resources are here.