I have been a member of WritersBBS for over ten years. I've made friends who I've met in person as well as being online friends, and I found a publisher via WBBS to keep my children's novels in print after the first publisher closed, and have found tons of help and encouragement over the years.
I belong to a couple more, including Hubpapges, but WritersBBS.com has been the longest running.
I have to jump in here to advertise my own site - I have a couple of hubs about it with the links to it. I made it to ADD to Hubpages articles - nad give a place for high quality articles, language learning aids, etc etc.