There are thousands of nonprofits in the United States, and many will happily allow teen volunteers. One way to find an appropriate program is simply to call a charity in which you're interested. They almost certainly have some task with which you can help.
You may not need to look any further than your local church. Many churches offer soup kitchens, community cleanup days, community education, support groups and other outreach programs. Similarly, your school or hospital probably have programs that could use an extra set of hands. If you're new to volunteering, such programs can provide a way to ease into volunteer work in a familiar setting.
If you're not sure which nonprofit to talk to, think about the areas in which you want to make a difference. Popular choices include animal welfare, hunger and poverty relief, education, environmentalism, work fighting discrimination and prejudice, human rights, disease outreach and education, disaster relief and politics. The organization Do Something classifies teen volunteer programs by area of social change -- you can likely find a program near you [source: Do Something].
Another option is to talk to local arts nonprofits. Many orchestras, choirs and theater companies operate as 501(c)(3) charitable organizations, and they almost always have extra work to do. They may not have a volunteer program in place (although some larger organizations do), but they could offer internships that work much the same way. You'll likely be able to learn about how nonprofit organizations work -- and you may get to see some wonderful art.
Finally, if you can't find an organization that matches what you want to do, try starting your own! Round up a few like-minded friends, research the problem you want to solve and take action. Web sites such as Idealist offer extensive information on starting a volunteer program, including online discussion groups for teens [source: Idealist]. Do Something is one of many programs that offer grants to teen start-up organizations [source: Do Something].
On the next page, we'll explore some of the benefits of volunteer work.