qb4usf has been organizing a round robin for the past 4 seasons (Dice Roll Invitational). His idea was to make it a kind of 'elite' D3 invitational so he would just send sitemails to folks who have had good teams in the previous season (based upon NT results I believe). Then he chose 4 teams other than himself based upon who was interested and told everyone to leave the first 5 games of their non conf open. Then later on he'd send the schedule.
That's about it! But, you'll need to do the previews and recap writeups like he does too though... they are crucial.
And I might be interested in an Allen D1 round robin - fyi