Being open is a great start!
if they are interested, find some good "Polyamory 1021" type articles and recommend they read them. That way they will see that this isn't just you being strange, but that there are a ton of other people out here who feel the same way.
Please check out The Birdcage - an open, friendly Polyamory forum for all parts of New York State
"Listen, or your tongue will make you deaf." - Native American Proverb