Overview
The HDFS Documentation provides the information you need to get started using the Hadoop Distributed File System. Begin with the HDFS Users Guide to obtain an overview of the system and then move on to the HDFS Architecture Guide for more detailed information.
HDFS commonly works in tandem with a cluster environment and MapReduce applications. For information about Hadoop clusters (single or multi node) see the Hadoop Common Documentation. For information about MapReduce see the MapReduce Documentation.
If you have more questions, you can ask on the HDFS Mailing Lists or browse the Mailing List Archives.