http://querytracker.net/index.php Yes it is a query site, but there are forums (groups) with good info
http://writeoncon.com/ a Forum writer's conference focused on picture book, middle grade and YA writers.
https://plus.google.com/ lots of writers are popping up on Goggle+ each day
http://www.rwa.org/ for you romantics out there Romance Writers of America
http://www.sfwa.org/ Science Fiction & Fantasy Writers of America
http://www.mysterywriters.org/ Mystery Writers of America - Wonder how many answers you would get at a meeting when asking who done it.
http://www.horror.org/ Horror Writers Association
http://absolutewrite.com/ seems like a good site, haven't spent much time here yet, but I will.