There are two threads on the RED User forum:

Digital cinema package – how i, a computer neophyte, made an open source dcp on my ma – REDUSER.net

This one has excellent data on preparing your audio and video materials: Digital Cinema Package – REDUSER.net

Film maker Chris Perry writes the A-Z on his site as well, which he recently updated: crumbs: Making a DCP entirely with open source tools (update)

Clyde has other articles on the site, one that explains Doremi’s CineAssist version 
Doremi’s CineAssist allows for in-house 3D DCP mastering

For a myriad of other DCinema best practices, especially focused on Stereoscopic 3D, see his blog:
http://www.realvision.ae/blog 

There are many restrictions in the open source model at this point. Alternative frame rates (anything other than 24 frames) is not easy…or perhaps not even possible if you don’t have a means of creating a JPEG 2000 version of your output…which is a requirement of the DCP. 

Knut Erik Evensen‘s site promotes his DCP mastering services and he also has an article on the open source capabilities, DCPC, a frontend to open source DCP tools.

Lars Reichel has a front end for DCP creation: Digital Cinema Package Creator

No matter how much reading you do, these techniques are not simple or for those without excellent computer skills. 

Still free, but possibly not open sourced, one cannot neglect the excellent work from the Fraunhofer Institute in Germany, centering a suite of products around easyDCP, easyDCP Creator, easyDCP Player and easyDCP Workflow Plug-Ins.

The sister company of the  Aussie integrators Digital Cinema Network is the developerment group digitAll, who have introduced the dcpPlayer for the desktop computer and are soon to release dcpEncoder. (digitAll is also a sister group to Cine Tech Geek, a great place to get practical demonstrations of digital cinema equipment and concepts.)