Pam Laricchia has a wonderful collection of writings on learning and living joyfully with kids. Especially for new unschoolers is the Exploring Unschooling download. It's an introductory series of short articles that prompt you to think in new ways about learning.
Like the Always Learning list, a discussion group for Radical Unschooling philosophy and practical ways to put it into practice. (Learn Nothing Day?! Be cautious clicking on July 24th. Learning is everywhere!)
This list is about recognizing the joy in living, loving, learning, and accepting our partners for who they are. It is for parents already radically unschooling who want to expand the respectful relationship to their partners.
Not an unschooling list, but alternatives to spanking, leaning heavily to peaceful parenting. It hasn't had much activity recently, but the archives are well worth a read if you struggle with calmness and peace in parenting.
Discussion of what helps and hinders children's learning. In 1999 the discussion started on Yahoogroups. In 2006 it moved to Google (to take advantage of a search function that actually worked). The better discussion has moved to Always Learning but the archives are still available.