Puppet is a1) powerful open source tool to automate the configuration of and software management on Unix-like2) operating systems. This posting is a distillate of the resources I collected during my Puppet learning phase. I hope it helps to get an overview about what Puppet can do for you and how to use it (plus providing existing Puppet users some new ideas or tips).
Links
Selected slides and presentations (overview, use-cases, experts, tips)
