The difference between polyamory and swinging is a difficult one since there are so many ways to do each one. I've known swingers who actually do what most would consider poly and self-proclaimed polyamorists who do what most would consider swinging.
I wish you luck in finding what you're looking for, and encourage you to make sure you know what YOU define polyamory as to make sure you can communicate that well to potential partners! lol Nothing more confusing than having 2 or more different, vague ideas of what is wanted (okay, there probably is stuff that's more confusing, but it's still pretty darn confusing!).
Welcome again, and enjoy the site!