Unfortunately, most documentation for the moment is for developers. There are also instructions regarding suitable Java software that is used to run Fenfire or compile it from source code.
However, we are happy to discuss the project, its vision and current software with prospective users and developers. You can reach us by sending mail to fenfire-dev@nongnu.org (mailing list fenfire-dev). Our IRC discussion takes place in channel #fenfire on the Freenode servers (e.g. irc.freenode.net) and discussion logs are available.
The project milestones document gives a summary of where we are at the moment.