First off, pbh, welcome!
Congrats on being so calm and brave about the whole situation. Poly can be scary territory the first time around, and it sounds like you're being mature and reasonable, which to me is a very good sign.
You're definitely right that you should form your own ideas about poly, and do some thinking and experimenting on what works for you. My best advice is to talk about EVERYTHING-- especially how you're feeling and where you feel like you have boundaries-- and to approach it all with an open mind.
Given your moniker (which I think is adorable, btw), I'd guess that recommending some reading material might help. As far as websites go, xeromag.com is a delightful one-- its essays on poly are really wonderful. There's also lots of books out there, and everyone has a different perspective on which one is best; preference seems based on the reader's spiritual and ethical beliefs, so it's hard to say which one will work for you. The most popular texts from what I've seen on here are The Ethical Slut
), Polyamory: The New Love Without Limits
(too New Age for my tastes, but it might be right for you), and Opening Up
(which I haven't read yet
). If you're of a sci-fi bent, then Heinlein's fiction might be inspirational. (As a queer feminist, I need lots of grains of salt before I can handle some of his asides, but poly, sappy me still weeps at the end of his best books.)
There's actually an entire thread on here about reviewing poly texts... I forget where, but I suspect it's easy to find.
Thanks for sharing, and keep posting. We'll be here for you.