polyamory

On this site:

Bisexuality and relationships
written as part of the bi-education section, but containing an explanation of what polyamory is

"Stereotypes" article by Darragh Doherty, originally published in
Gay Community News, Ireland
also from a bi perspective but mainly about polyamory.

Polyamory themed button badges
from the "Identity" badge collection at Uncharted Worlds:
over 40 designs, including
"And the princess fell in love with the other two princesses,
and they all lived happily ever after"

On other sites:

A good place to start is www.polyamory.org.
Polyday is a UK one-day festival.