Please note that none of the sites provides enough information to learn to use a particular method of NFP. In order to use any method effectively, you need proper instruction by someone trained to teach the method. Most of these sites have information on how to receive such instruction in person, by correspondence course, on-line course, or over the telephone (or some combination of these).
The Couple to Couple League (CCL) is the most prominent Catholic organization devoted to teaching NFP. Founded in 1971, it is now the largest provider of information on NFP in the United States, and it has chapters in 23 other countries. CCL estimates that approximately 107,000 families have learned NFP through one of their courses.
CCL provides instruction in the sympto-thermal method. Their website includes pages explaining how NFP works, rates of effectiveness, the morality of NFP, links to search for teachers in your area, and a link to their catalog. If you are unable to locate a teacher nearby, they offer a correspondence course. CCL has an extensive Spanish-language outreach.
Northwest Family Services (NFS) is a nonsectarian organization that has been teaching NFP for over 25 years. On its website, NFS has information about the sympto-thermal method of NFP, in which they provide instruction. NFS goes beyond NFP education with programs programs in marriage preparation and building lasting relationships. NFS also offers marriage and family counseling, as well as programs to support young people in making "healthy and life-giving choices." They provide an online catalog for ordering materials and an online course. In-person courses are available in a limited geographic area. Like CCL, NFS offers Spanish-language services.
The Creighton Model FertilityCare System (CrMS) website provides a wealth of information about the background and effectiveness of this mucus-only method of NFP. You can read about the advantages of the system and find an extensive bibliography of published articles in a wide variety of medical journals which detail the scientific foundations of CrMS. While CrMS holds education programs each year in Omaha, Nebraska, it trains teaching couples who offer local course. Help in finding a local teacher is also available through the website.
Founded in 1997, the Institute for Natural Family Planning (INFP) provides teacher training, research and scholarship in NFP, and "innovative NFP services." Among the latter is INFP's biggest contribution to NFP technology: the ClearBlue Easy Fertility Monitor, "a device used at home which measures hormone levels in urine to estimate the beginning and end of the time of fertility in a women's menstrual cycle."
The Marquette Model website explains how the method, which includes other elements of traditional NFP methods, works and how to use it. It includes sections on avoiding pregnancy, achieving pregnancy, special circumstances, and the benefits of NFP. Contact information is provided to get in touch with local instructors.
At the World Organisation of the Ovulation Method Billings (WOOMB) website, you can find extensive information about how one of the best-known NFP methods, the Billings Method, works, as well as information on effectiveness and contact information. The WOOMB website includes information about achieving and avoiding pregnancy and using the method while breast-feeding. Through the website, you can take online courses in the Billings Method as well as create personal charts to help you determine your fertility.
On their website, the Family of the Americas Foundation (FAF) offers help with conceiving a child, avoiding pregnancy, discontinuing artificial methods of birth control, and navigating a return to fertility after breast-feeding. FAF offers NFP teacher-training programs in over 100 countries in North America, Europe, Africa, Latin America and Asia, including the People’s Republic of China. You can order materials for learning and using FAF's NFP method and search for an instructor in your area. Phone instruction is available if there is no instructor nearby.
One More Soul (OMS) is not an NFP organization per se, but the OMS website offers a nearly comprehensive listing of NFP-only doctors. Many of those who practice NFP find it more comfortable to use an NFP-only doctor. You can search the directory by state or by specialty. OMS also offers information on reversal of sterilization for men and women, as well as a listing of doctors who perform such procedures. The website also provides a job-listing board for NFP-only physicians and nurses.