Setting up a Hadoop cluster involves plenty of repetitive work. Ambari offers a Web-based GUI with wizard scripts for setting up clusters with most of the standard components. Once you get Ambari up and running, it will help you provision, manage, and monitor a cluster of Hadoop jobs. The image at left shows one of the screens after starting up a cluster.
Ambari is an incubator project at Apache and is supported by Hortonworks. The code is available at http://incubator.apache.org/ambari/.