Ann Brown & Joseph Campione's Guided discovery in a community of learners,
This is a chapter in K. McGilly (1994) Classroom lessons: Integrating cognitive theory and classroom practice (pp. 229-270). Cambridge, MA: MIT Press/Bradford Books. It is a good source for understanding the authors' methods and rationale for developing community of learners. However, it does not appear to be available online any more. 8/4/05.

George Lucas Educational Foundation
This site offers an online version of the magazine Edutopia (also available in a print version). GLEF focuses on innovative classrooms, skillful educators, and involved communities. The PBL section gives you access to archived stories, movies, and interviews about projects that work. This is a great site and this foundation does a lot to support PBL.

Sylvia Chard's project approach
The project approach in early childhood and elementary
education. Especially worthwhile is the short section on The classroom: A community of learners,. This page gives suggestions for learning communities involved in project-based learning.