CraftBoard
A general discussion forum for crafters working with all types of materials. Includes instructions, tips, information about materials, questions and answers.
http://craftboard.50webs.com/

CraftRevolution.com
Helps crafters and buyers connect through discussion and shared resources. Articles, forums, and shopping guides.
http://craftrevolution.com/

Craftster.org
Forum covering a range of crafts including clothing, crochet, interior decorating, jewelry, knitting, paper crafts, silk screening and quilting.
http://www.craftster.org/