I like xeromag.com and I like lovemore.com
I also found the book that Mono always suggests very helpful and very "they aren't becoming poly but want to know what's wrong with you" person friendly if you know what I mean.
Opening Up and Ethical Slut are aimed more at someone who WANTS this lifestyle whereas Love Without Limits is more aimed at educating....
Good luck-big hug!
"Love As Thou Wilt"