Franklin's pretty awesome. http://www.xeromag.com/franklin.html
Now that I look at it, I think someone else recommended his More Than Two site.
I really enjoy reading Polyamorous Misanthrope columns. She's got some great common sense answers to polyamorous questions. http://www.polyamorousmisanthrope.com/
There is a lot of information about polyamory in the news here http://polyinthemedia.blogspot.com/
and usually at least one reference to a book worth reading.
And of course the typical reading list has The Ethical Slut, and Opening Up. I confess that I lost my attention span before reading either, but I have read A Tribe of Hearts about Pagan polyamory, and I enjoyed it. If you wander over to Amazon and type in one of the titles I gave you, it will usually pop up other suggestions. Sadly, unless you live in a progressive town, I don't think your library is going to have any of them. Mine didn't.
Sex at Dawn isn't about polyamory so much as human sexual relationships but it sounds fascinating. That one might be in a library, and I would think it might shed some light on the monogamous vs. polyamorous relationship models.