Greetings Lizzy and Kenny,
Welcome to our forum.
I think the biggest "rules" about poly are to be thoroughly honest and communicate with each other about your feelings, limitations, etc.
There are many "shapes and sizes of poly" (different numbers of people, configurations of intimacy connections, amounts of commitment, etc.), so you'll just want to find out what fits right for you.
You might find our Life stories and blogs board
helpful, it tells people's life stories and gives you an idea of what some real-live poly situations really look like, how they function, what works, what to watch out for, etc.
And we have things like a Poly Relationships Corner
and a General Poly Discussions board
, where you can post your thoughts and questions (and of course you can do your own blog too if you want).
Just let us know how we can help as you go along.