You can find different Christian ministries by consulting a Web directory, such as the Domain Directory of Christian Organizations and Educational Institutions of the Institute for Christian Leadership. You can also search for ministries within a certain tradition, such as Catholic ministries on Catholic Culture and the Official Catholic Directory.
The Domain Directory of Christian Organizations and Educational Institutions lists a wide range of Christian organizations, from the American Family Association and Shalom Israel Foundation to the American Scientific Affiliation and American Center for Law and Justice. Note that these organizations represent different Christian traditions (such as Baptist and Lutheran), and so vary in terms of doctrine and practice.
The Official Catholic Directory has a short list of Catholic ministries and links to their websites. Entries include Catholic Charities, the Catholic Youth Organization of the Archdiocese of Indianapolis, the Organizations for Catholic Young Adults and the Totus Tuus Catholic Youth Organization.
Catholic Culture provides a unique service through its reviews of websites of Catholic ministries. The Catholic Culture rating system looks at factors such as each ministry and organization's website usability, quality of resources, and fidelity to Catholic doctrine and practice. You can go through Catholic Culture's directory to see how different ministries align with the Catholic faith.