The MCH Library (http://www.ncpad.org/656/2706/2004-01-01), a virtual guide to maternal and child health information located at the National Center for Education in Maternal and Child Health (NCEMCH) at Georgetown University, offers a wide variety of electronic resources, including the MCH Alert, knowledge paths, publications, databases, bibliographies, and other materials developed for health professionals, policymakers, and families. The center recently announced a new edition of its knowledge path about physical activity for children and adolescents. This electronic resource guide points to a selection of resources that analyze data, describe public health campaigns and other promotion programs, and report on research aimed at identifying promising strategies for improving physical activity levels within families, schools, and communities along with materials that describe the consequences of sedentary behavior. It is aimed at health professionals, policymakers, educators, coaches, and families and is available at http://www.ncpad.org/656/2706/2004-01-01. Knowledge paths on other maternal and child health topics can also be viewed at http://www.ncpad.org/656/2706/2004-01-01.