What is Puppet ?
Puppet is very powerful configuration management software. Using it can make your life a lot easier if you manage more than a dozen systems. The end user community is very active in Puppet. Every year there is PuppetConf, which hosts training and other sessions of interest. After you start using Puppet and become comfortable with it, you should look into contributing to the Puppet community. Writing modules is an easy way to give back to the community.
With the advent of the cloud infrastructure, you can use Puppet to deploy to Amazon, Google Cloud, Rackspace, and perhaps other cloud providers as well. From provisioning to management, Puppet can be your friend.