Cities around the country are building systems that seek to make the most of public and private resources to provide widespread, high-quality, out-of-school time opportunities. Local officials are leading these efforts because participation in OST programs not only benefits young people but also the cities in which they live, with the potential to support many city priorities--from reducing crime to creating a more skilled workforce. However, even with growing public awareness of the importance of OST as a learning and developmental support, millions of children, especially the neediest, are missing out on these opportunities, with an estimated 15.1 million children returning to an empty house at the end of the school day. This guide provides municipal leaders and their key partners with strategies for collecting and using information to strengthen citywide OST systems. The six strategies presented here are intended to help build the capacity of communities to get and use information across a citywide system: (1) Collect attendance and participation information to support access, enrollment and quality improvements; (2) Conduct market research to assess family, youth and community needs; (3) Use geographic information system (GIS) technology to identify service gaps and improve access; (4) Develop, adapt and implement a citywide program quality assessment tool; (5) Conduct and support program and city-level evaluation efforts; and (6) Develop common, system-wide outcome measures/indicators. (Contains 3 footnotes and 14 resources.)