An orphanage houses children whose parents have abused them, died or abandoned them. A variety of agencies can run them: private, religious or governmental. In the United States, most orphanages have been renamed "children's homes." Working or volunteering your time in an orphanage is a wonderful way to positively impact the lives of children who need it the most. Orphanages are notoriously underfunded, thus, they will most likely appreciate any contribution of your time that you can offer.
Visit the website www.orphanage.org. It will give you a comprehensive listing of every orphanage and children's home in the United States or abroad that it knows about.
Contact the orphanage in the area of the world that you'd like to work in. Some orphanages will only accept volunteers, in which case you should explain in what area you'd like to help: tutoring, teaching music classes, performing construction on site, gardening, etc.
E-mail or fax your resume or CV to desired orphanages if you have qualifications in an area where they have job openings such as administration, social work, child psychology, etc.
Ask about required immunisation you might need to receive before working in an orphanage abroad, and get those before travelling.
Budget your money. If travelling abroad, verify that you have enough money for a plane ticket and living expenses for the amount of time that you'll be there, especially if you will just be doing volunteer work. Make sure that you know whether your orphanage will provide accommodations.
Budget your time. If working in the U.S., set a schedule with the orphanage which you will follow as a volunteer. Both the institution and the children will be relying on you, and you want to provide them both with a stable schedule that you can easily follow.