The proliferation of customer-facing data-intensive systems in almost every modern enterprise has catalyzed the rapid deployment of big data environments, commonly with Hadoop as the underlying processing environment. Unfortunately, infrastructure and operations (I&O) pros have had little guidance in understanding how to configure and manage the underlying infrastructure to support Hadoop and its ecosystem of tools and applications. This report helps I&O professionals understand the basics of Hadoop infrastructure and includes guidelines for system configuration, rough data sizing, and suggestions on how to plan for the inevitable growth of the Hadoop big data environment.