This group is the main discussion forum for the UK's poly community and also has a dating subgroup. It is a closed group so people on your Facebook will not be able to see what you say in the group but will be able to see that you are in a group called UK Polyamory.
UK poly websites and resources: For more general info about polyamory and other useful links.
Webcomics, articles, and reading lists: Kimchi is a great poly webcomic. The list of arcticles, blogs, journals, and books on More than Two is extensive. Poly is also attracting a lot of media attention as this recent BBC guide shows.