There are some useful food and wine sites which I consult, and I reluctantly have a presence on such as facebook and linkedin, only so that my contact details are out there, but I don't belong to any forums or discussion groups.
UKAuthors.com and my website.
My Space and Face book.
I read Writer's Digest and Writer's Market, but I don't share on line much. Only with other writer friends personally in emails.
I don't tend to rely on internet sources for much of my information, since a lot of the sites are unreliable. In the event that I do use it, I simply use Google to bring up websites and then check multiple sources. I do tend to visit news sites, like FOX or CNN, quite frequently, though.
I find myself frequenting Facebook.com, along with my blog:
"Pravda", "Yahoo News Of The Odd", and "Bartcop.com" are my main sources of information. I share with no one. Get your own.
Facebook, blogspot and friendster.
Las Vegas Advisor, Las Vegas News Blog,Southwest Airlines,Vegas.com, LVCVA, and Steve's Everything Las Vegas..among others.
Twitter/Yahoo/ youtube/various social networks.
Facebook because my friends are almost exclusively writers and poets. Also, http://www.gotpoetry.com is a great site for upcoming poets.
Mainly Blogspot, Hubpages, Twitter and Facebook.