To respond effectively to state and federal policy changes, city leaders, non-profit service providers, advocates, and researchers all need accurate data on how federal funds flow to local governments. Unfortunately, those data are spread across multiple sources that are often indecipherable or inaccessible to non-experts. The purpose of this guide is to help data users navigate the patchwork of primary data sources and online portals that show how the federal government distributes funding to local governments. We drew on the literature, an inventory of online resources, interviews with local and federal officials, and Urban Institute research staff experience to catalog available data on federal-local transfers. We describe the strengths, weaknesses, and best uses of various data sources and portals and provide guidance on where users can find information to understand trends or how their community stands relative to its peers. Our guide concludes with simple recommendations for how to improve data quality, comparability, and usability at all levels of government.