The Forum at Pottery.About.com
Beth Peterson, your Pottery Guide here at About.com, moderates this forum for potters, those interested in pots, and those who would like to find out more.
Clay and Ceramics Forum
As they say, the Clay and Ceramics Forum "is for those working with clay and ceramics to discuss techniques, materials and how to get the clay out from under your fingernails."
Crystalline Glaze Forum
This forum is for those who love and work with macrocrystalline glazes. Since crystalline glazes can very difficult, this forum / discussion group is great to help with problems.