Welcome to opsi!
If you are new to opsi, the getting started manual will help you install and set up.
A virtual machine with installed opsi server and a short tutorial can be found on opsi.org.
The general manual can be found here.
The opsi community meets in the opsi-Forum. There you can also find the link to the opsi wiki.
All manuals are available for download as PDF or standalone HTML at download.uib.de.