Theresa Testoni of Silver Spring has mentored a young woman with intellectual disabilities for two years. They go shopping, to the movies, out for pizza. They see each other twice a month and talk weekly, but even that amount of time has had a big impact. One evening when Testoni was dropping the 24-year-old off, the young woman skipped to her door.

“It brought tears to my eyes,” says Testoni, 42. “I spent an hour and a half of my time, but I was able to bring so much joy to this young woman.”

Being part of a young person’s growth can be a life-changing experience to both parties. One of the top mentoring groups is Big Brothers Big Sisters (bbbs.org) , with offices in DC and Fairfax, and the counties of Arlington, Prince William, and Prince George’s. Paul Bliss, president of Big Brothers Big Sisters of the National Capital Area (301-794-9170 ext. 11; bbbsnca.org) , says there are two main ways to mentor a child: through school-based or community-based programs.

A school program is an hour-a-week commitment and includes supervision. Volunteers in community programs usually commit at least four hours a week after a background check and orientation. After you’re paired, you can take part in educational, recreational, or cultural events.

“A Big Brother or Sister’s primary goal is to help broaden the horizon for a youngster,” Bliss says, “to help them experience the richness of what Washington has to offer.”

Other groups include Best Kids (202-397-2999; bestkids.org) , where volunteers mentor children in foster care; Northern Virginia AIDS Ministry (703-533-5505 ext. 15; novam.org) , in which mentors are paired with children affected by HIV/AIDS; and Bridges to Pals (301-424-0656; www.mhamc.org; click on “volunteer opportunities”), for at-risk youth and children with disabilities.

Best Buddies (800-89-buddy; bestbuddies.org) , the program Testoni volunteers with, is a “mutual mentoring” program: High-school and college students are matched with students who have disabilities, adults with adults. The Virginia branch doesn’t offer adult mentoring because of funding, but Maryland does.

To learn more about other groups, go to Mentor/National Mentoring Parntership’s Web site, mentoring.org.