Crayola Art Education: Ideas and lesson plans for incorporating art across the curriculum.
DLTK's Crafts for Kids: Free printable templates for children's crafts suitable for preschool, kindergarten and grade school.
Early Childhood Art Activities: Classroom-tested ideas. Includes list of items with which kids can paint.
Elementary Art Lesson Plans: Traditional art lesson plans, computer graphics lesson plans, technology hints, and teacher hints.
KinderArt: Free art lesson plans for use with young children.
Kinderart Littles: Art education for children of all ages. Parents and teachers contribute ideas, tips, projects and recipes for art and sensory activities. Sister site lists projects for K-12.
Lesson Plans Art Project Index: Resource for teachers and people working with children, including ideas for arts and crafts projects, receipes, tips and professional advice.
NNCC Favorite Recipes for Art Materials: Recipes for making play-dough, paints, hardening clay, and bubble solution.
Open Ended Art: Activities for early childhood classrooms. Includes photos of and directions for the projects.
Preschool Education Art: List of thematic art activities for young children.
Toddlers and Preschoolers - Art for Kids Net Links: Links to art and music activities for young children.