I'll be happy to answer any questions the best I can.
Do note that our triad started a bit differently...we really didn't have a long-term couple plus one scenerio, like you're doing. It was more of a guy (M) dating two guys (R and C) off and on simultaneously and then bringing everyone together as a group. (We've now been together just over two years.)
Nonetheless, I totally understand what you mean about seeing lots of info about MMF or MFF triads, but not much about MMM triads.
If you have any specific questions, let me know. In the meantime, I highly recommend this article "Tips for Triads": http://sexgeek.wordpress.com/2010/03...ks-for-triads/
It has helped me in many many ways to navigate this experience.