Here's some great sites about Polyamory

Polyamory.com - Resources for Poly's & those who love them
Love Energy - Love Energy Unlimited
Loving More - Polyamory Headquarters - Loving More, the Magazine of Polyamory, Polyfidelity, and Expanded Family.
Alt.Polyamory - This is a home page for the Usenet newsgroup alt.polyamory.
Polyandproud - Playful and provocative polyamorous paraphernalia.
The Polyamory Society - Serving the Polyamorous Community.
Polyamory Related Books - Polyamory Books -- Reviews of Books about Polyamory.
Poly people on ICQ -
The Poly Matchmaker - The Perfect Place to Find Your Poly Mate.
Polyamory- What? Why? How?
UUPA -Unitarian Universalists for Polyamory Awareness
Polyamory -Alternatives to Marriage
World Polyamory Association
Poly-Friendly Professionals - A list of professionals who have been referred here, or who have identified themselves as being, open-minded about polyamory and polyamorous issues.
Institute for 21st Century Relationships - abundant love, alternative lifestyles, polyamory, open marriages.