Sorry there is no users guide so far, but you can probably find the information in the FAQ or try asking on the mailing list.. There are also some man pages included in the distribution that might help.
Here is a diagram that provides a high level architectural overview of the typical OpenCALEA scenario and how the various processes relate with each other. (.txt)
There is a discussion list for both discussions regarding the opencalea
software tools as well as exchanging implementation experiences.
Send email to: firstname.lastname@example.org
As the text of the msg send: subscribe opencalea
The mailing list archives can be found at: http://www.merit.edu/mail.archives/opencalea
After you are subscribed to the list you can send email to the list at the address: email@example.com