This brief is designed to help data intermediary organizations develop and improve part of the data management process known as ETL (Extract, Transform and Load). It provides advice and lessons learned from organizations in the National Neighborhood Indicators Partnership that successfully use ETL techniques. It is important to periodically review the ETL process to ensure current practices are efficient, producing high quality data, and meeting the organization's and community's needs. Case studies from five organizations are included to illustrate the ETL process in practice.