This document provides an overview of strategies and resources for assisting patrons with data reference questions. It discusses John Snow's 1854 cholera map, examples of common data reference questions, and a five question framework for the data reference interview process. This includes determining the type of data needed, relevant variables and populations, geographic and time frame requirements, and data access and use conditions. Government agencies, data portals, and statistical resources are presented. Tips are offered for pairing with another librarian to practice sample questions using the interview framework.