For myself, I've found that three relationships feels like a good upper limit right now. The things that have been most helpful are Google Calendar for scheduling time together, and this from BP for keeping my head on straight: http://www.polyamory.com/forum/showp...84&postcount=8
Don't forget to leave your self sufficient time to rest and do chores and such.
If people are briefly scandalized they will get over it, don't worry.
The major players. Me, 30ish bi female. Gia, girlfriend of 4+ years. Clay, boyfriend/dom. Davis, ex/friend/"it's complicated." Eddie, roommate & fwb.
The supporting cast. Eric, Gia's husband. Bee, Gia and Eric's toddler. Dexter, Gia's lover. Helen, Eric's lover. Izzy and Nikki, Clay's partners. Liam, Eddie's husband.